Step 1

Crush the digestive biscuits in a food bag with a rolling pin or in the food processor. Melt the butter in a saucepan, take off heat and stir in the brown sugar and biscuit crumbs.

Step 2

Line the base of a 20cm loose bottomed cake tin with baking parchment. Press the biscuit into the bottom of the tin and chill in the fridge while making the topping.

Step 3

Beat together the mascarpone, caster sugar, lemon zest and juice, until smooth and creamy. Spread over the base and chill for a couple of hours.