Preheat the oven to 180ºC/160ºFan/Gas 4/350ºF Grease and line a 20cm baking tin.
Put the flour, sugar and cocoa powder into a bowl and mix until uniform in colour.
Pour in the melted butter and combine until the mixture resembles breadcrumbs. You can use your hands to do this.
Tip the mixture into the prepared tin and press it down firmly using your hands.
Sprinkle the top of the mixture with a tablespoon of cold water. Bake in the preheated oven for 18 minutes. Remove from the oven and sprinkle over 2 teaspoons of granulated sugar. Leave to cool in the tin.
Slice into 4 squares and then into 8 triangles.
Serve with pink, chocolate or mint custard.
Video
Notes
Press the mixture hard into the tin otherwise, it won't be crunchy. Chocolate Concrete can be served hot or cold. It will be a softer consistency when it comes out of the oven and will become crunchy as it cools and hardens. Serve with pink, chocolate or mint custard. See the blog post to find out where to buy the custard and for the mint custard recipe. Store in an airtight container at room temperature for up to 5 days. Can be frozen for up to 3 months.
Keyword Chocolate Concrete, Chocolate Crunch, School dinners