Preheat the oven to 375 degrees(F).
In a large mixing bowl, whisk together the flax meal and water. Let it sit for 3 to 5 minutes or until it thickens. This creates a flax egg.
Pour the non-dairy milk and olive oil into the bowl. Whisk together with the flax egg until fully combined.
Put a sifter over the bowl with the wet ingredients, then add the flour, baking powder and baking soda into the sifter and sift the dry ingredients into the wet ingredients.
Pour the salt into the bowl. Then stir everything together until fully combined and there are no dry spots of flour left.
Drizzle a little olive oil into a 9x9 inch square baking dish and then spread it out evenly to coat the bottom and sides of the pan using a brush or paper towel.
Then scoop the dough into the pan. It will be very sticky. I like to just wet my fingers with water or a little olive oil, then spread the dough out evenly into the pan.
Top the dough with the pizza sauce, spreading it out evenly. Then spread the vegan cheese and vegan pepperoni on top evenly.
Bake for 15 minutes. Then take another pan, preferably one that will fit inside the pan with the pizza. Spray or brush the bottom of that pan with oil. Then place it on top of the pizza. This is optional, but I love how much it helps brown the top.
Bake for another 10 to 15 minutes or until the top is brown and melty and the bread is cooked through.
Let cool for a few minutes and then cut into squares.