Preheat your oven to 350 degrees Fahrenheit. Mix together 1/4 cup of carob powder, 1/4 cup of rice flour, 1/4 cup potato flour and 1/2 cup white sugar. In a separate bowl, beat together 3/8 cup of butter or margarine with one large whole egg. Add the egg mixture a little at a time to the dry ingredients. Beat these together until the mixture is smooth. Once they are combined, stir in the gluten-free semi-sweet chocolate chips. Pinch out a small amount of dough, and using your hands, roll the dough into small balls or a cookie scoop. These will be placed on a greased cookie sheet. Press a fork in a criss-cross shape using the tines. Bake the cookies for 10 minutes. Remove them from the oven and allow them to cool before serving.