In a large bowl, combine the all purpose and whole wheat flour, sugar, baking powder, baking soda and salt.
In a separate bowl, beat together the egg, sour cream, butter and vanilla. Slowly stir in the dry ingredients until fully incorporated. Fold in the chocolate chips.
Scoop the batter into a paper-lined muffin pan and bake for 18-20 minutes or until a toothpick inserted comes out clean.