Use the Atkins recipe to make Atkins Flour Mix for this recipe.  You will need 2 cups (eqivilent to 6 servings, with each serving equal to 1/3 cup flour mix) to make 18 biscuits.Preheat oven to 425°F degrees.Blend together Atkins Flour Mix, baking powder, sugar substitute and salt in a large mixing bowl.Cut butter into small chunks and add to the dry ingredients, using a pastry blender or your fingertips to work until the mixture resembles coarse crumbs. Do not over-mix.Pour in heavy cream and stir lightly. Coat cutting board with olive oil spray. Using a spatula, transfer the dough to a cutting board. Coat hands with oil spray and lightly knead dough a few times until blended. Do not over knead.Pat out dough into a circle 1/2 - 3/4-inch thick. Using a biscuit cutter with a 2¼-inch diameter, form biscuits. Make an extra biscuit out of scraps instead of re-rolling the dough.Place biscuits on a baking sheet coated with oil spray. Brush tops with melted butter, if desired.Bake 15 - 18 minutes or until golden brown.Remove biscuits from oven and place on a wire rack to cool.