Preheat your oven to 425°F. Place the potatoes directly on the oven rack and bake for about 50 minutes, or until fork-tender. Let them cool for 10 minutes before handling.
While the potatoes cool, stir together the tomato sauce, Italian seasoning, garlic powder, salt, and pepper in a bowl. Set aside.
Slice the potatoes in half lengthwise. Scoop out the centers, leaving a ¼-inch border around the edges (save the scooped potato for mashed potatoes or soup).
Place the skins cut-side down on a wire rack over a baking sheet. Brush with olive oil and bake for 10 minutes.
Flip the skins over and spread a little seasoned sauce inside each one. Fill with mozzarella, pepperoni, and basil.
Return to the oven and bake for another 10 minutes, or until the cheese is melty and bubbly.
Let cool for a couple minutes before serving. For extra flair (and flavor), wrap each one in a large basil leaf before eating.