115g(1/2 cup / stick) unsalted butter, cubed and chilled
FOR THE CHOCOLATE CUSTARD
70g (2.5oz) dark (50-70%) chocolate, finely chopped
1cup whole milk
2tablespoons thickened (heavy) cream
2tablespoons(30g) unsalted butter
1/3 cup granulated white sugar
3/4teaspoon vanilla extract
2tablespoons corn flour (cornstarch)(notes)
1teaspooncocoa, for dusting
FOR THE CHOCOLATE PASTRY
Place the flour, cocoa and sugar in a food processor and pulse 2 times to combine
Add the chilled butter and blitz for about 20 seconds until the lumps are quite small (1-2mm). Add the egg and process another 15 seconds to combine.
Pull the dough together with your hands and shape it into a disk. Wrap in plastic wrap and chill for 1/2 and hour.
Preheat the oven to 180C / 350F / 160C fan forced. Grease the holes of a 12 hole muffin tin.
Roll the dough out on a very lightly floured surface to about 3mm thickness. Use a 10 cm round cookie cutter to cut rounds of dough (try not to reroll too many times). Cut a small triangle out of one edge only about (2cm deep) so each round looks a bit like a pacman. Push the rounds into the holes of the muffin tin. Place in the fridge. (notes)
Poke holes in the bottom of each shell with a fork then bake for 10 minutes (while making the custard filling)
FOR THE CHOCOLATE CUSTARD
Melt the chocolate in 30 second bursts in the microwave, stirring well between each until melted and smooth. This should not take more than 1 1/2 to 2 minutes.
Pour the milk and cream into a heavy based saucepan, and add the butter, sugar and vanilla, then heat on very low heat until the sugar has dissolved, stirring regularly.
While the milk mixture is heating, mix together the water and cornflour until smooth. Pour it into a large bowl (or the bowl of a stand mixer) and add the egg yolks, then beat on high until light and doubled in volume.
Once the sugar has dissolved, turn the beater down to low and pour the milk mix in a slow steady stream into the egg mix. Don’t pour it too quickly or the heat will scramble the eggs.
Once all the milk is added to the eggs, return the entire mix to the saucepan. Heat over low heat, stirring with a balloon whisk constantly, until it gets very thick. This will happen quite suddenly after about 5 minutes or so, so it’s important to keep gently whisking increasing intensity as it gets very thick. You will end up with lumpy custard if you don’t.
When the custard is very thick, remove from the heat and add the melted chocolate. Whisk until everything is smooth and well combined. The custard should be of a consistency that drops off the whisk in blobs (rather than running off in a stream).
Fill the pastry cases with custard and bake for about 20 minutes until the tops look dry and cracked.
Once cool, dust with cocoa and top with fresh raspberries, shaved chocolate and the pastry offcuts if you made any.
I use a standard Australian 20ml tablespoon (= 4 teaspoons worldwide)
Use the pastry offcuts to cut out more little shapes like hearts or flowers to decorate the finished tarts with too.