INSTRUCTIONS
1. Preheat oven to 425o F. Heat butter and 3 tablespoons olive oil in a medium saucepan over medium-low heat until butter is melted. Add garlic, pepper flakes and oregano; continue cooking, stirring occasionally, until garlic is softened but not browned, about 2 minutes. Stir in half of parsley and salt. Remove from heat.
2. Place bread, cut side up, on a rimmed baking sheet. Press down on bread evenly until compressed to about 2/3rds of original height. Brush half of garlic/butter/oil mixture evenly over the surface of the bread, making sure to get bits of garlic and seasoning on each piece.
3. Add crushed tomatoes to the remaining garlic/butter/oil mixture in a small pan; stir to combine. Increase heat to medium until it boils, then reduce to simmer.Cook until reduced, about 15 minutes. Spread sauce evenly over bread.
4. Sprinkle ½ cup mozzarella evenly over surface of bread and return to oven for about 10 minutes or until cheese is melted. Remove from oven and sprinkle with Parmigiano-Reggiano cheese and remaining parsley. Allow to cool slightly and serve.