1. Preheat oven to 190C. Place 12 muffin paper cases in a muffin tin.
2. Sift the flour, cocoa and baking powder together into a large bowl. Stir in sugar.
3. Whisk the egg, milk and melted butter together, then getly stir into the flour mixture to form a stiff batter. Fold in the marshmallows and chocolate chips.
4. Spoon the mixture into the muffin cases.
5. Bake muffins in preheated oven for 20-25 minutes until well risen. Leave to cool in the tin for 5 minutes, then transfer to wire rack and let cool completely.
6. eat, enjoy, serve, and accept compliments ;)