Preheat the oven to 180C/160C Fan. Lightly grease a 12-hole mini loaf tin (or cupcake tin if you don’t have one).
In a mixer fitted with a paddle attachment, beat together the butter and the brown sugar in a large bowl until they come together.
Add the eggs one at a time, whisking well after each addition.
Add the flour, baking powder and cocoa. Stir through until you have a lovely dark cake mix.
Roughly chop 100g of the chocolate and add to the mixture along with the Rodda’s Cornish clotted cream. Stir to combine.
Transfer the mixture into the prepared tin.
Bake for 20-25 minutes until a skewer comes out clean. Remove the mini cakes from the oven and leave in the tin for about 5 minutes before tipping these out onto a wire rack to cool completely.
Meanwhile to make the icing, beat together the remaining Rodda’s clotted cream with the icing sugar. Place in a piping bag fitted with a star nozzle then pipe over the tops of each mini cake. Grate or curl the remaining chocolate and scatter over the cakes before serving.