Heat the oven to 450°F and line a baking sheet with parchment paper.

Set aside about 4 ounces of the dough. Roll the remaining dough into a 12-inch round or rectangle and place it on the prepared sheet.

Shape the reserved dough into 4 small rectangles to resemble tombstones and set them on the baking sheet beside the main crust.

Heat 1 tablespoon olive oil in a skillet over medium heat. Add the sausage and cook until browned and crumbled, about 6 minutes. Drain any excess fat.

Brush the main crust lightly with the remaining olive oil and sprinkle with garlic powder. Spread the pizza sauce over the crust, then top with 1½ cups of the mozzarella.

Scatter the cooked sausage and sliced mushrooms evenly over the cheese. Tuck the tombstone dough pieces upright into the toppings so they stand slightly above the surface.

Sprinkle the remaining mozzarella around the base of the tombstones. Bake for 12 to 15 minutes until the crust and tombstones are golden and the cheese is bubbly.

Remove from the oven and let rest 5 minutes before slicing.