perfect chocolate muffins

The best chocolate muffins I've ever made. I've ever eaten. 

300 g flour
4 tablespoons cocoa
1,5 teaspooon baking soda
3/4 cup of sugar
250 ml buttermilk
2 eggs
200 g dark chocolate
100 g melted buter
pinch of salt

Mix dry ingredients in a bowl. Add wet ingredients to the dry ones,  mix it. Pour into cupcake pan (12 liners).
Bake at 180C degrees for 20-25 minutes.