Preheat your oven to 180C/350F, line a 12 hole muffin pan with paper cases
Sift the flour, baking powder and cocoa into a large mixing bowl
Stir in the sugar, salt, chocolate chips and orange zest
Whisk together the oil, milk and marmalade
Make a well in the flour mix and pour in the liquid, stir well to combine and pour into the muffin cases.
Bake in the preheated oven for 20-25 minutes until risen. If you poke them with a skewer it should come out clean (unless you hit a chocolate chip - poke them in a couple of places to be sure!)
Cool in the tin for 5 minutes before transferring to a wire rack to cool completely.
Notes
Nutritional information is only an approximate guideline. Calculations will vary according to the ingredients you use and your cooking methods.