Preheat oven to 425°F. Grease a baking sheet with 1 tablespoon of olive oil.
Roll pizza dough out into a 12-inch circle and transfer to the prepared baking sheet.
In a small bowl, combine remaining 2 tablespoons of olive oil, garlic, oregano, and red pepper flakes (if using). Brush the garlic mixture over the surface of the dough.
Sprinkle mozzarella cheese over the top. Drizzle marinara sauce over the cheese.
Bake for 20 minutes or until golden brown. Cut into slices and serve.