Stir the butter, olive oil, salt, garlic powder, Italian seasoning, and black pepper together in a small bowl. The finished mixture should look evenly seasoned and soft enough to brush.
Set the oven to 350°F and get your muffin tin or individual muffin cups ready. Use eight spaces for the eight biscuit cups.
Apply a light coating of cooking spray or oil to the cups, then blot any puddles with a paper towel. The bottoms should have a thin sheen rather than visible pools of oil.
Separate the packaged biscuits and gently press one across the bottom and up the walls of a cup. Keep easing the dough back into position as it contracts until it holds the cup shape.
Shape each remaining biscuit in its own muffin cup. Look for an even dough lining across the base and sides.
Pierce the dough bases and walls in several places with a fork. These small openings help release trapped air instead of letting bubbles push the filling upward.
Spread the seasoned butter mixture over the inside of each biscuit cup with a pastry brush. A thin, even coating gives the walls garlic flavor without collecting at the bottom.
Brush about a heaping ½ teaspoon of pasta or pizza sauce over the buttered interior. The dough should show through a light coating of sauce.
Add a heaping tablespoon of mozzarella to a cup, followed by a heaping ½ tablespoon of chopped pepperoni. The cheese forms the first layer beneath the meat.
Build another layer with 1 tablespoon of mozzarella and ½ tablespoon of pepperoni. The alternating layers distribute cheese and pepperoni throughout the filling.
Add a pinch of Italian seasoning over the filling if desired. This optional topping leaves a light scattering of herbs on the cheese.
Fill the remaining dough cups using the same layering order. Keep the portions consistent so no cup towers far above the others.
Arrange individual foil cups on a sheet pan before putting them in the oven. The firm support keeps the flexible cups level during transfer.
Bake for 20 to 23 minutes, watching for browned biscuit rims and melted mozzarella. The crust edges should be golden and the cheese should look gooey and bubbly.
Carefully release the cups from the muffin pan and transfer them to a plate or platter, or serve them in their individual foil tins. Lift gently to keep the tender biscuit walls intact.