In large bowl combine flour, sugar, and cocoa powder.
In separate bowl mix together melted margarine, egg, milk, and vanilla.
Pour wet ingredients into dry ingredients and stir to mix well.
Stir in chocolate chips.
Divide batter among greased muffin cups or a muffin tin lined with muffin papers.
Bake at 400 degrees for 20 minutes. Makes about 18 muffins.