Pour the blueberries, sugar and juice into a medium saucepan. Heat over low heat stirring every so often allowing it to come to a simmer. Once simmer, turn the heat down to the lowest setting and let it simmer away for about 20 minutes, swirling the pan every so often, until thick and glossy and the blueberries have broken down.
Place in the fridge to cool completely before using.
For the cupcakes
Preheat your oven to 180C / 350F (160C fan) and line your muffin tins with paper cupcake cases
In a bowl, sift together the flour, corn flour, baking powder and salt. Add the lemon zest and mix well to combine.
In a separate bowl or the bowl of a stand mixer, beat together the melted butter and sugar until smooth.
Add the eggs one at a time, scraping down the sides of the bowl each time and beating well after each. The mixture should look smooth and silky. Add the vanilla and mix well to combine.
Add 1/3 of the flour mixture to the butter and sugar mixture. Stir through gently until only just combined. Now add half of the milk and the lemon juice. Mix gently again. Continue like this until all the flour and milk is combined… just. It is important not to overmix or be too heavy handed otherwise your cupcakes will turn out dense and tough.
Fill the cupcake cases to about 3/4 full. Bake in the oven for around 20-22 minutes, turning the pan around in the oven half way through to make sure they bake evenly. When a skewer inserted comes out with just a crumb or two, they are done.
Cool in the tin for 5 minutes before turning out onto a cooling rack. Let the cupcakes cool completely before proceeding.
For the cream cheese frosting
In a stand mixer with a paddle attachment, beat the butter and cream cheese, along with ½ cup of the icing sugar for about 5 minutes, until light and fluffy. Scrape down the sides regularly and continue beating.
With the mixer on low, add another 2 1/2 cups of the remaining sugar 1 spoon at a time until combined. If the mixture needs to be a little thicker, add in the last 1/2 cup of icing sugar.
Scrape down the sides of the bowl. Add the salt, vanilla, lemon zest and cream and beat for 5 minutes at medium speed until it looks light, thick and creamy.
Use a sharp knife or a cupcake corer, to cut a hole in the top of each cupcake.
Fill each hole with about 1 teaspoon of blueberry compote. Top it off with a little bit of the cupcake offcuts to seal it in.
Transfer the cream cheese frosting to a piping bag and pipe a big dollop on top of each cupcake.
Top the cupcakes with little fresh blueberries (or one large one)
Add 1-2 teaspoons of water to the remaining compote and push it through a strainer so you just have the juice. Drip the juice over the top of the blueberries so it drips down.
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).