Preheat oven to 425°F. In a large skillet, warm oil over medium heat. Add the diced onion and sauté until translucent, about 2-3 minutes.

Add the ground beef, and cook until browned and cooked through (about 6-7 minutes), crumbling the meat as it cooks. Once the beef is fully cooked, remove it from the heat and drain the grease from the skillet.

Add salsa, chili powder, cumin, garlic powder, and salt to the beef, and stir until everything is combined. Set aside.

Grease a rimmed baking sheet, then arrange 6 of the tortillas so they cover the bottom of the baking sheet, but also hang over the sides of the sheet pan at least 5-6 inches.

Spread the beef mixture evenly over the tortillas, leaving room on the edges to fold the tortillas over to cover the beef.

Sprinkle the shredded cheese over the beef mixture.

Place the last tortilla in the center of the quesadilla, then fold the 6 bottom tortillas over so that everything is encased in tortillas.

Brush the top of the sheet pan quesadilla with more avocado oil, then set another baking sheet on top of the tortillas to keep them from opening while baking.

Bake in the preheated oven for 25 minutes, then remove the second baking sheet. Bake an additional 5 minutes, or until the top of the quesadilla is browned.

Cut into squares, then serve with avocado, more salsa, and sour cream!