01 - Preheat oven to 350°F. Grease a 9x13-inch baking dish with cooking spray or butter.
02 - Cut the refrigerated biscuit dough into 1-inch pieces and scatter them evenly in the prepared baking dish.
03 - In a medium bowl, combine the biscuit pieces with 1 cup of pizza sauce and half of the mozzarella cheese. Toss gently until evenly coated.
04 - Spread the coated biscuit pieces evenly across the bottom of the dish. Pour the remaining 1/2 cup pizza sauce over the top.
05 - Layer pepperoni, black olives, and bell peppers over the biscuit base.
06 - Sprinkle the remaining mozzarella cheese and cheddar cheese evenly over all toppings.
07 - Evenly distribute Italian herbs, garlic powder, crushed red pepper flakes (if using), salt, and black pepper over the top.
08 - Bake uncovered for 30 to 35 minutes until biscuits are puffed and golden brown, and cheese is melted and bubbly.
09 - Let the casserole rest for 5 minutes before serving to allow the cheese to set.