I think this strawberry sheet cake is my favourite cake ever! Definitely the best strawberry cake I’ve ever made and it will be my go-to from now on. With real strawberry flavour, creamy frosting and the most amazing texture, you’re going to love this one.
Why you’ll love it
This strawberry sheetcake, well actually a quarter sheet cake, has everything you need in a strawberry cake.
Strawberry cakes are difficult to get strawberry flavour into without adding fake flavourings but I was determined to give this real flavour.
What sets this strawberry cake apart from the rest is the strawberry puree reduction. You can use fresh or frozen strawberries but reducing the puree down means you’re concentrating all the flavour of the strawberries without having to deal with extra moisture.
In testing this recipe, I first started with regular puree straight into the batter. Let me tell you, it was still a gorgeous cake but a bit ‘meh’ on the strawberry scale. I didn’t want fake flavourings and jams are ok but add extra sweetness. I wanted real strawberries and reducing the puree adds more real strawberry flavour into the cake than you could get otherwise.
Yes, it adds a little bit more time to the recipe but it’s not difficult at all. If you really don’t want to do that, just use straight strawberry puree. You won’t get as much flavour that way but still have a beautifully moist and soft cake. The silky, creamy frosting packs a strong strawberry punch too.
On top of that, I’ve also used buttermilk to keep it tender and oil to keep it moist. I’ve combined everything in this one to result in the fluffiest, light and moist strawberry cake you’ve ever tried.
Ingredients you’ll need
A few basic baking ingredients and some fresh and freeze-dried strawberries are going to make this strawberry sheet cake the best you’ve ever tried.
Detailed quantities and instructions in the recipe card below.
- Fresh strawberries: Plump fresh and ripe strawberries are what you need. Out of season, you’d be better off using frozen strawberries which tend to be a little sweeter than out of season fresh strawberries. You can even use those strawberries that are past looking their best in this cake. Since it’s all pureed, you don’t see that. Trim off any clearly bruised parts but soft strawberries are fine.
- Freeze-dried strawberries: To get a strong strawberry flavour into the frosting without having to deal with extra moisture, use freeze-dried strawberries. With all the water removed, they are literally all strawberry flavour.
- Flour: Use regular plain flour / all-purpose flour here or cake flour in it’s place.
- Cornflour / cornstarch: So that I don’t need to keep cake flour on hand (which is a combination of plain flour and cornflour), I make my own. I add a little cornflour / cornstarch to many of my cakes to add softness to the cake.
- Sugar: You only need one sugar for the cake and the frosting. I use white caster sugar but white granulated sugar is fine too.
- Eggs: I use large eggs. Get free-range if you have the means.
- Buttermilk: Tangy buttermilk adds moisture and tenderness to the cake.
- Butter: Just regular unsalted butter so you can control the salt level.
- Pure vanilla extract: Vanilla + strawberry = loveliness.
- Baking powder and baking soda: Baking powder and baking soda (bicarb soda) are used in this cake for a combo leavening. It results in such a fluffy cake.
- Salt: Just a little salt for balance, always.
- Oil: Vegetable oil like sunflower or a very light flavoured olive oil works to keep this cake moist.
- Milk: The frosting uses some milk in it and creates a creamy smooth frosting.
How to make strawberry sheet cake
Want to know how to make the best strawberry cake with real strawberry flavour? Don’t skip step one.
Detailed instructions in the recipe card below.
- Puree and reduce: Puree fresh strawberries, then push it through a strainer into a saucepan. Now cook that puree, letting it simmer away for around 20 minutes until it’s very thick and reduced to half a cup. You could technically skip this step but you won’t taste any strawberry flavour in the cake without it.
- Dry ingredients: Whisk together the dry ingredients in a medium mixing bowl and set aside.
- Wet ingredients: Start by creaming together softened butter, oil and sugar until it looks pale and creamy. Add the eggs one at a time, beating each time until smooth. In a small jug, combine the reduced strawberry puree, buttermilk and vanilla.
- Combining the batter: Add a third of the flour to the butter mixture and beat on low until just combined. Add ½ the buttermilk mixture and mix that through. Now repeat that but just fold with a spatula each time which will prevent overbeating the mix.
- Bake: Tip the batter into a prepared 9×13 baking pan and bake for around 28 minutes or until a toothpick comes out with just a crumb or two attached.
How to make strawberry ermine frosting
Ermine frosting – it’s absolutely my favourite type of frosting. Also known as cooked milk or milk and flour frosting, I think the flour in it confuses people, or maybe the granulated sugar, but my oh my, this is the most wonderful frosting ever invented.
- Silky smooth – no graininess at all.
- Ultra creamy
- Less sweet than regular frostings and buttercreams
So how do we make it?
Detailed instructions in the recipe card below.
- The flour paste: Start by heating together milk, flour and half the sugar over low-medium heat, whisking constantly to keep it smooth, until it turns into a thick paste. At this point you’ll think I’m crazy but please trust me. Let this paste cool to room temperature – you don’t want it either hot or cold.
- Beat butter and sugar: Things start to look a little more normal now. You’ll beat together butter and granulated (or I prefer caster / superfine sugar) until light and creamy. Add the flour paste in, one big spoonful at a time, beating until each is combined before adding the next. Now beat it for a good 4-5 minutes on medium.
- Add flavour: Add some salt, vanilla and freeze-dried strawberry powder (it’s worth it, I promise) and beat to combine well.
- Because this frosting gets quite aerated, I find it useful to use a spatula to press it against the side of the mixing bowl to push out some of the air bubbles. This way it spreads better.
I promise, even though you’re using granulated sugar, it is a smooth as silk. The sugar dissolves completely (unlike icing / powdered sugar). And it doesn’t taste of flour. The flour flavour is cooked out during the flour paste cooking and you won’t taste it at all.
Tips and tricks
Here’s some tips for the very best strawberry sheet cake ever!
- Don’t overbeat the batter: This is really important when making cakes. Overbeating the batter will develop gluten and make your cake tough or dense so, once you add the flour, just gently mix it in until it’s just combined.
- Reduce the puree: We’re going for real strawberry flavour in this cake – not fake flavourings – but strawberry is a subtle flavouring in a cake. The way you amp up the strawberry flavour is by reducing the puree until it’s thick and just strawberry flavour without excess liquid. You can skip the reduction but you won’t be able to taste any strawberry.
- Your frosting hasn’t split! Ermine frosting reacts differently because it is so different and at some point, you’re bound to look at it and think it’s split. This is normal. Just keep on beating and it will come together into this creamy, silky, gorgeous buttercream.
- Freeze-dried strawberries: These add so much flavour. Technically, you could make this frosting using the same method I did for this raspberry ermine frosting, using fresh fruit but freeze-dried strawberries, while possibly a little more expensive, are much easier to incorporate.
This cake will keep well for 4-5 days in the fridge in an airtight container. It freezes well too. Let it thaw at room temperature for ½ an hour.
If you try this strawberry sheet cake recipe, please take a moment to leave a rating and comment below. I love hearing from you, and it helps other readers too!
More recipes you’ll love
- Strawberry Crumb Cake
- Jam and coconut sponge
- Strawberry sponge cake
- Coconut and Raspberry Cake
- Lemon Ricotta Cake
- Fluffy Vanilla Cake
- Vanilla sponge tray bake
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FOR THE STRAWBERRY CAKE
- 260 g plain (all-purp) flour (2 cups / 9.2oz)
- 35 g cornflour (cornstarch) (¼ cup / 1.2oz) (notes)
- 1 ½ teaspoons baking powder
- ½ teaspoon baking soda (bicarb soda)
- ½ teaspoon salt
- ¼ cup vegetable oil 60ml
- 300 g granulated sugar (1 ½ cups / 10.5oz)
- 113 g unsalted butter, softened (½ cup / 1 stick / 4oz)
- 3 large eggs, room temp
- ¾ cup buttermilk, room temp (180ml)
- 450 g fresh ripe strawberries (1lb)
- 2 teaspoons vanilla extract
- pink food colouring (optional)
FOR THE STRAWBERRY ERMINE FROSTING
For best results, always weigh ingredients where a weight is provided
- Stand mixer or handheld electric mixer
- medium saucepan
- spatula and mixing bowl
- FOR THE STRAWBERRY SHEET CAKE: Place the strawberries in a blender and blend to a puree. Strain them through a sieve into a medium saucepan.
- Heat the puree on medium heat and let it simmer for 15-20 minutes, stirring often until it has reduced right down to half a cup. Transfer to a small bowl and chill just until it reaches room temperature or just over (notes).
- Preheat the oven to 180C / 350F / 160C fan forced. Grease and line a 9×13 tin with baking paper. If your tin has short sides, make sure the paper comes up past the top edge by an inch or so.
- In a medium mixing bowl, whisk together the flour, cornflour, baking powder, baking soda and salt to lighten and evenly disperse. Set aside.
- Add the eggs, one at a time, beating each until the mixture is smooth. Scrape down the sides of the bowl from time to time.
- In a jug, mix together the strawberry puree, buttermilk and vanilla.
- Add ⅓ of the flour mixture to the butter and egg mix. Beat on low or stir until just combined. Follow with half the buttermilk mixture, mixing until just combined.
- Now, using a spatula, not the mixer, repeat the process using three more instalments – flour, buttermilk, flour – mixing each time until just combined. If using colouring, add a couple of drops with the last amount of buttermilk.
- Pour the batter into the prepared baking tin and gently spread out evenly all over. If you make the centre slightly lower than the edges, you’ll end up with a flatter cake surface as the centre does rise.
- Bake for around 28 minutes. Start checking 3-4 minutes before by poking with a toothpick – it’s done when the toothpick comes out with just a crumb or two attached.
- FOR THE STRAWBERRY ERMINE FROSTING: Whisk the flour, milk and half the sugar together in a small saucepan until smooth. Heat over a low-medium heat, continuing to whisk slowly so that it doesn't form lumps, until it gets very thick (like a pudding or thick custard).
- Transfer the mixture to a bowl and cover with plastic wrap pressed to the surface. Cool this mix to room temperature (notes 7).
- Beat together the butter and remaining ½ cup sugar until really creamy – about 3-4 minutes. Scrape down the bowl a few times through the process.
- Add the cooled flour paste a large spoonful at a time, beating on medium until each spoonful is incorporated before adding the next.
- Once the paste has all been added, mix on medium for another 5-6 minutes. If it looks like it separates, don’t worry, just keep on beating. It will all come together into a beautiful, almost whipped cream looking frosting.
- Once the frosting looks whipped and light (and not split), add the freeze-dried strawberry powder, vanilla and salt. Beat on low just to incorporate then stop.
- Optional: To remove some of the air-bubbles from the frosting and make it more smooth, use a spatula to press it up against the sides of the bowl a few times.
- Top the cooled cake with the frosting, then decorate with extra strawberries.
- I use a standard Australian 20ml tablespoon (= 4 teaspoons worldwide)
- For best results, you should always weigh ingredients like flour and sugar. Kitchen scales are relatively cheap but if you can’t weigh the ingredients, use the spoon and level method (don’t scoop).
- All ovens vary – check your cake for doneness 3-4 minutes before the recipe suggests.
- You can swap both the plain flour and cornflour for cake flour.
- The puree must be cooled to around room. If your buttermilk is still quite cold, then it’s ok if the puree is still a touch warm as they’ll even each other out when you combine them.
- You can make this cake without reducing the strawberry puree but you won’t be able to taste strawberry in the cake. If you want to skip the reduction, you only need ⅓ cup of non-reduced strained strawberry puree.
- It’s important to cool the flour and milk paste to room temperature before adding to your butter. While you can cool it more quickly in the fridge or freezer, it must be room temperature before using it – neither hot nor cold.
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