Preheat oven to 400° and line a medium baking sheet with parchment paper.
Drizzle cut side of spaghetti squash with olive oil and season with salt and pepper. Place cut side down on the baking sheet and bake until tender, 45 minutes to an hour, depending on the size of your squash. Reduce heat to 375°F when finished baking.
Let cool for 10 minutes before using a fork to shred the squash into spaghetti pieces. Place into a bowl and combine with parmesan and garlic powder. Season with salt and pepper.
Transfer 1/4 c squash to a greased muffin pan, pressing down on bottoms and side to create cups. Place in the oven to bake, 15 minutes.
Spoon pizza sauce into each cup, top with mozzarella and mini pepperonis. Bake again, 8-10 more minutes, or until cheese is melted.
