Crunchy Chocolate Caramel Layer Cake

Preheat oven to 180°C (350°F). Line 2 large baking trays with non-stick baking paper. Place the flour, cocoa and sugar in a food processor and pulse to combine. Add the butter, water, egg and extra yolks and process until a smooth dough forms. Turn out the dough and bring it together on a lightly floured surface. Divide into 8 equal pieces. Roll each piece into a very thin rectangle and trim to 10cm x 35cm. Prick each layer all over with a fork and place on the trays. Bake for 8–10 minutes or until just crisp. Transfer to wire racks and allow to cool at room temperature until crisp.

To make the chocolate caramel filling, place the sugar and water in a medium saucepan (see note) over medium heat and stir to dissolve the sugar. Bring to the boil and cook for 8–10 minutes or until deep golden in colour. Remove from the heat and, working quickly, add the cream in a thin steady stream. Add the butter, return to the heat and cook, stirring, until well combined. Place the chocolate in a heatproof bowl, pour the caramel mixture over and stir until melted and smooth. Refrigerate until just cold, whisking occasionally. Once cooled, whisk for 1–2 minutes or until creamy and smooth.

To assemble, place 1 of the pastry layers on a cake stand or plate. Spread evenly with 1/3 cup (80ml) of the chocolate caramel filling. Repeat with the remaining pastry and filling, finishing with a pastry layer. Refrigerate the cake for 1–2 hours or until set. Slice to serve.