Hawaiian Chantilly cake

Step 1: Heat the oven to 350°F (300°F fan) and line two 23 cm round tins. Whisk the 9 oz plain flour, 2 ⅛ oz cocoa powder, 10 ½ oz sugar, 1 ½ tsp bicarbonate of soda, 1 tsp baking powder and ½ tsp salt.

Step 2: Beat in the 2 eggs, 1 cup buttermilk, ½ cup vegetable oil and 1 tsp vanilla extract, then whisk in the 1 cup hot coffee or hot water to a thin batter. Divide between the tins and bake 30–35 minutes until a skewer comes out clean. Cool completely.

Step 3: For the frosting, whisk the 1 ½ cups evaporated milk, 7 oz sugar and 5 egg yolks in a heavy pan. Cook over a medium-low heat, stirring all the time, for 15–20 minutes until it turns light caramel in colour and as thick as pudding.

Step 4: Off the heat, stir in a third of the 2 ⅝ oz butter and the 1 tsp vanilla extract. Cool to room temperature, stirring now and then.

Step 5: Beat the rest of the 5 ½ oz butter until fluffy, then beat in the cooled custard a spoonful at a time until smooth and spreadable. A common mistake is adding warm custard, which melts the butter.

Step 6: Sandwich the cakes with a third of the frosting and cover the top and sides with the rest. Scatter with 1 ¾ oz macadamia nuts and chill for 1 hour to set. Keep in the fridge.