Preheat the oven to 200C/180C Fan/Gas 6. Line a 10 hole mini loaf tin.
In a large bowl, combine the flour, baking powder, cocoa powder and sugar.
Make a well, and pour in the milk, egg, oil and butter (make sure it has cooled a little first). Add the chocolate chips and stir gently with a wooden spoon until just combined.
Scoop the batter into the lined tin. Bake 15-20 minutes, until golden and a skewer inserted comes out clean. Let cool on a wire rack before eating!