Sour cherry-chocolate cookies

1.Preheat oven to 180C. Beat butter and sugars in an electric mixer until light and fluffy (2-3 minutes), add eggs and vanilla and beat well to combine. Sift over flour, cocoa, bicarbonate of soda and ½ tsp salt, stir to combine, then stir in chocolate and sour cherries. Roll heaped tablespoons of mixture into rough balls, flatten slightly and place on baking-paper-lined oven trays, leaving plenty of room for them to spread. Bake until puffed and starting to set (8-9 minutes). Cool slightly on tray then transfer to a wire rack to cool completely. Cookies will puff while baking and flatten while cooling.

2.Meanwhile, for chocolate ganache, bring cream and crème de cacao to the boil in a small saucepan, remove from heat, add chocolate, stand for 1 minute, stir until smooth. Cool until thick and spreadable (1-2 hours), then sandwich pairs of cookies together with ganache and stand until set. Cookies will keep in an airtight container for up to 3 days.