Sauté mushrooms and onion in 1 tablespoon olive oil and 1/2 teaspoon garlic powder (save the remaining 1/2 teaspoon for later) until onion begins to turn transparent (just a few minutes). Drain excess liquid; set aside. On a lightly floured surface, shape dough into a ball, then roll out to a 9-inch circle. Place dough to fit in a greased heart shaped pan (9-12-inches). If you do not have a heart shaped pan, use a 12-inch circular pizza pan or cookie sheet or cut a large heart shape from a 12-inch circle of parchment paper and place on a greased cookie sheet. Pierce dough several times with fork. Bake in preheated 375° oven for 5 minutes. Increase oven temperature to 425°. Top dough with both cheeses, the remaining 1/2 teaspoon garlic powder and rest of toppings. Bake at 425° for 15-20 minutes or until crust is golden brown and cheese is bubbling. Remove from pan to wire rack and serve.