Instead of brushing with butter and dipping in caster sugar, toss the doughnuts in icing sugar before adding the lemon curd or chocolate toppings. If dipping in lemon glaze, leave the doughnuts plain.
Lemon Curd and Mascarpone
Gently fold together 150 grams mascarpone with ½ cup lemon curd.
Stir together 1 cup of icing sugar with a little lemon juice until thick and smooth.
Heat 150ml cream then add 100 grams chopped dark chocolate. Stir until smooth, then cool. Top with chopped pistachios.