Chocolate Chip Muffins

This is the first time I've tried a muffin recipe which doesn't use any butter, sunflower oil is used instead. The muffins turned out fine, but think I still prefer the buttery kind.
Ingredients:
300g plain flour
225g sugar
1 tablespoon baking powder
2 tablespoon cocoa powder
2 eggs
115ml sunflower oil
175ml milk
chocolate chips
1 teaspoon vanilla essence
1)Preheat oven to 180 degree celsius
2) Mix all dry ingredients, except chocolate chips, together (flour, sugar, baking powder, cocoa powder)
3) Combine all wet ingredients in a bowl and beat with an electric whisk until combined.
4) Add dry mixture and chocolate chips to wet mixture and stir until just combined.
5) Spoon batter into 12 muffin cups placed in a muffin tin and sprinkle some chocolate chips on top of each one. Bake for about 20 minutes.