Preheat oven to 190 C/ 170 C fan/ gas mark 5/ 375 F and line a 12 hole muffin tin with paper baking cases.
Sift 150 grams plain flour, 3/4 tsp bicarbonate of soda, 90 grams granulated sugar, 90 grams light brown soft sugar and 1/4 tsp chilli powder together in a large bowl.
Measure out 30 grams cocoa powder, 115 ml water and 60 grams butter into a small saucepan and heat gently over a low heat until the butter has melted and the ingredients are combined. Do not allow this to boil!
Measure out 75 ml full fat milk1/2 tsp distilled white vinegar and whisk 1 large free-range egg into it. Add 1/2 tsp Madagascar bourbon vanilla bean paste.
Add the melted chocolate mixture and the egg mixture to the dry ingredients and stir to combine well. The batter will be thin.
Spoon into the prepared baking cases and bake for 20 minutes until well rise and springy. A wooden skewer inserted into the centre of the cakes will come out clean when done. Transfer to a wire rack to cool completely.
Frost with 400 grams chocolate fudge frostingand sprinkle with as many (or as few!) crushed chilli flakesas you'd like.