Preheat oven to 350F. Line a large cookie sheet with parchment paper.
In a large bowl, whisk together the coconut flour, almond flour, psyllium husk powder, baking powder, and salt.
Stir in egg whites, oil and apple cider vinegar. Slowly pour hot water over, stirring until dough expands.
Turn dough out onto a silicone mat or a large piece of lightly greased parchment paper and pat into a rectangle. Top with another piece of parchment paper and roll out to a large 12 by 15 inch rectangle.
In a small bowl, whisk together the tomato paste, water, salt, pepper and garlic powder. Spread evenly over dough, leaving a 1-inch border. Sprinkle dough with pepperoni, mozzarella and parmesan, leaving a 1-inch border.
Starting at a long end, slowly roll up dough tightly using the silicone mat or greased paper to help you. Pinch the seam to seal.
With a sharp knife, cut into 15 or 16 even slices. If your rolls get a little squashed, you can reshape them after cutting.
Lay rolls on prepared baking sheet and bake 32 to 40 minutes, until puffed and set. Bake as long as you can without burning the cheese and tomato sauce (they still may deflate a bit upon cooling).
Let cool on pan.
Serves 15. Each roll has 6.92 g of carbs and 4.21 g of fiber. Total NET CARBS = 2.71 g.Food energy: 139kcal Saturated fatty acids: 4.46g Total fat: 8.79g Calories from fat: 79 Cholesterol: 19mg Carbohydrate, by difference: 6.92g Total dietary fiber: 4.21g Protein: 7.02g Sodium: 392mg