Preheat oven to 190 degrees C. Prepare a greased baking tray.
In a medium bowl, cream butter and sugar. Gradually add egg substitute and vanilla while mixing. Sift together gluten free flour, bicarb soda, baking powder and salt. Stir into the butter mixture until blended. Finally, stir in the chocolate chips.
Using a teaspoon, drop biscuits 5cm apart on prepared baking tray. Bake in preheated oven for 6 to 8 minutes or until light brown. Let biscuits cool on baking tray for 2 minutes before removing to wire racks.