Step 1

Place apple, 2 tablespoons sugar and 2 tablespoons water in a saucepan over low heat, stirring, for 8-10 minutes until the apple is soft. Allow to cool.

Step 2

Meanwhile, place custard powder, milk, vanilla extract and the remaining 1 tablespoon sugar in a small saucepan and stir to form a smooth paste. Place the pan over low heat, then cook, stirring, for 4-5 minutes until the custard comes to the boil and thickens. Remove from the heat and cover the surface with plastic wrap to prevent a skin forming. Allow to cool, then whisk in the mascarpone.

Step 3

Spread 8 biscuits with the custard mixture, then top with a dollop of stewed apple. Stack 2 of these on each of 4 plates, then top with remaining biscuits to form 4 stacks. Dust with the cinnamon sugar and serve.