Ingredients – makes 12 biscuits

For the biscuits:

• 250 g plain flour, plus extra for dusting
• 50 g ground almonds
• 200 g butter
• 120 g sugar
• 2 egg yolks

For the vanilla custard buttercream filling:

• 150 g softened butter
• 200 g icing sugar, plus extra for dusting
• 3 tbsp vanilla custard powder

Method

Make the biscuits:

• Tip the flour, ground almonds and butter into a food processor and whizz to fine crumbs. When not using a food processor: rub the flour and ground almonds into the butter between your fingers until they form fine crumbs.
• Add the sugar and egg yolks, then whizz to a smooth dough. When not using a food processor: knead the sugar, egg yolks and buttery flour crumbs to form a smooth dough.
• On a lightly floured work surface, roll out the pastry to a thickness of about 5 mm and cut into 24 squares.
• Put the squares on baking trays lined with baking parchment and cool for 30 minutes in the fridge.
• Heat the oven to 180C/160C fan/gas 4 and bake the biscuits for 20 minutes.
• Remove from the oven, put on wire racks and leave to cool.

Make the filling:

• Sift the icing sugar and custard powder into the softened butter, mix thoroughly until smooth.
• Pipe some buttercream onto a biscuit, then sandwich with another biscuit.
• When all the biscuits are ready, dust with the extra icing sugar.