As soon as I read the words custard butter cream I knew I'd be making this, its my new favourite slice and you don't even need to turn the oven on, bonus. I made it to share with friends, we drank coffee and nibbled on little triangles of chocolatey custardy perfection while sitting in front of their open fire, our bellies full of slow cooked lamb and cous cous. The big and the little people agreed this one is a winner, a total crowd pleaser and did I mention the custard butter cream ...
1/2 cup (113g) butter
1/4 cup (50g) sugar
1/3 cup (30g) cocoa powder
1 large egg, lightly beaten
1 tsp pure vanilla extract
2 cups (200 grams) crushed digestive biscuits
1 cup (65g) coconut
1/2 cup (50g) nuts (I used almonds), coarsely chopped
1/4 cup (56g) butter, room temperature
2 - 3 tablespoons milk or cream
2 tbsp (20g) vanilla custard powder
1/2 tsp pure vanilla extract
2 cups (230g) icing sugar
120g dark chocolate (70% cocoa)
1 tbsp butter
Spray and line a 23 x 23 cm slice tin.
Start with the bottom layer, in a saucepan over low heat, melt the butter. Remove from heat and stir in the sugar and cocoa powder and then gradually whisk in the beaten egg, drizzle it in slowly. Return the saucepan to low heat and cook, stirring constantly, until the mixture thickens, about one minute. Remove from heat and stir in the vanilla extract, biscuit crumbs, coconut, and chopped nuts then press the mixture evenly onto the bottom of the prepared tin. Cover with gladwrap and refrigerate until firm (about an hour).
For the middle layer use your electric mixer, or with a hand mixer, beat the butter until smooth and creamy. Add the remaining ingredients and beat until the mixture is smooth. If the mixture is too thick to spread, add a little more milk or cream. Spread the filling over the bottom layer, cover, and refrigerate until firm (about an hour).
Now the last layer, chop the chocolate into small pieces and in a heatproof bowl, over a saucepan of simmering water, melt the chocolate and butter. Spread the melted chocolate evenly over the custard butter cream layer and refrigerate for about 15 minutes or just until the chocolate has set. Using a sharp knife, cut into squares, if the chocolate cracks when you try to slice it up leave it for a few minutes at room temperature and try again.