Preheat oven to 375°F (190°C).
In a large skillet over medium-high heat, brown the ground beef and onion until meat is fully cooked; drain excess grease.
Stir in 1/2 cup of pizza sauce, Italian seasoning, and garlic powder into the beef mixture; simmer for 2 minutes.
Spread 1/2 cup of pizza sauce onto the bottom of a 9x13 inch baking dish.
Distribute the beef mixture evenly among the 8 tortillas, adding 1 tablespoon of mozzarella to each before rolling tightly.
Place tortillas seam-side down in the baking dish.
Pour the remaining pizza sauce over the tortillas and top with the remaining mozzarella cheese.
Arrange pepperoni slices and black olives over the cheese layer.
Bake for 20 to 25 minutes until the cheese is melted and the edges of the tortillas are slightly crisp.