Preheat oven to 350 degrees. Line a muffin tin with 6 paper liners. In a medium sized bowl add gluten free master baking mix and cocoa. Stir together and add milk, egg, agave, and vanilla. Stir wet ingredients into dry ingredients. Fold in chocolate chips. Fill muffin tins 3/4 full with batter. Bake for 17-20 minutes until muffins are golden brown and a toothpick inserted in the middle comes out clean.