Flatten each biscuit into a 3-in. circle and press into a greased muffin cup. Combine the tomato sauce and Italian seasoning; spoon 1 teaspoonful into each cup. Top each with a slice of pepperoni and about 1 tablespoon of cheese. , Bake at 425° until golden brown, 10-15 minutes. Serve immediately or store in the refrigerator.