Place pizza stone or heavy baking sheet on center rack of oven. Preheat oven to 450 degrees.
In a large bowl, whisk together flour, baking powder, salt and choice of flavor add-ins. Make a well in the center and add water and oil. Stir until just combined then turn out onto a lightly floured work surface and knead 4-5 times.
Cut into 2 equal pieces. Place each on parchment paper and roll until about 3/8-inch thick. Brush lightly with olive oil and sprinkle with sea salt (optional). Slide onto un-rimmed baking sheet, then slide parchment/dough onto pizza stone. Bake for 3-4 minutes. Slide parchment paper back onto un-rimmed baking sheet and add favorite toppings. Return to oven and bake an additional 6-8 minutes until the cheese is melted and bubbly. Cool slightly before serving.