1. Remove the dough from refrigerator. Let stand at room temperature, covered, for 30 minutes.
2. Place a pizza stone or heavy baking sheet in oven. Preheat oven to 500° (keep pizza stone or baking sheet in oven as it preheats).
3. Combine 1 1/2 tablespoons olive oil and sliced garlic in a large skillet. Heat over medium-high heat 1 1/2 minutes or until the garlic begins to sizzle. Add 6 cups spinach; sauté 2 minutes or until spinach wilts. Set aside.
4. Combine cheeses, milk, and minced garlic in a bowl.
5. Roll dough into a 14-inch circle on a lightly floured surface, and pierce entire surface liberally with a fork. Carefully remove pizza stone from oven. Sprinkle cornmeal over pizza stone; place dough on pizza stone. Spread cheese mixture over dough, leaving a 1/2-inch border. Bake at 500° for 10 minutes or until crust is golden and cheese is lightly browned. Top with spinach; bake an additional 2 minutes or until thoroughly heated. Remove from oven; brush outer crust with remaining 1 1/2 teaspoons oil. Cut into 6 large slices.