01 - Preheat your oven to 350°F and grease a 9x13-inch baking dish with cooking spray or butter.
02 - Slice 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, tossing until evenly coated.
04 - Spread the coated biscuit pieces evenly across the bottom of the dish, then pour the remaining pizza sauce over the top.
05 - Layer the pepperoni, black olives, and bell peppers over the sauced biscuit base.
06 - Sprinkle the remaining mozzarella and cheddar cheese evenly over all the toppings.
07 - Distribute the Italian herbs, garlic powder, crushed red pepper flakes (if using), salt, and black pepper over the cheese layer.
08 - Bake uncovered for 30-35 minutes, or until the biscuits are puffed and golden brown and the cheese is melted and bubbly.
09 - Remove from the oven and let the casserole rest for 5 minutes before serving to allow it to set.