Preheat the oven to 180°C/gas mark 4

Rub the butter into the flour until it resembles coarse breadcrumbs. Stir in the caster sugar

Add the egg and mix until everything comes together. Form into a ball, which should be soft and smooth - add a drop of water if it's too dry

Roll the dough out to approximately 4-5mm thick. Using a cutter larger than the mini muffin pan / tart pan cells, cut out 12 circles (I used a 68mm plain cutter)

Press each circle gently into the tin. Prick the base of each twice with a fork

Bake in the oven for approx 12 minutes, until lightly browned. Remove from the tin and allow to cool

Crush the raspberries with the caster sugar. Spoon a little of the crushed raspberry mixture into the base of each tart case

Make the filling by whisking the melted chocolate together with the mascarpone, cream cheese and lemon zest, until thick and smooth

Spoon or pipe the creamy filling into the tart cases and pop a raspberry on top. Dust with a little icing sugar before serving