1. Preheat an outdoor grill to high heat for indirect cooking, about 450 to 475°F, or medium-high heat for direct cooking around 400°F. For indoor cooking, heat a grill pan over medium-high heat.

2. In a medium mixing bowl, combine the ground beef, Italian seasoning, onion powder, garlic powder, crushed fennel seeds, salt, and black pepper. Mix gently with your hands until evenly combined.

3. Divide the mixture into four equal portions and shape them into patties about 1/4 inch thick. Press a small indent into the center of each patty.

4. Place the patties on the grill and cook for 4 minutes.

5. Flip and cook for another 2 to 3 minutes.

6. Add a slice of mozzarella to each patty and cook for 1 to 2 minutes more until the cheese melts.

7. Transfer the burgers to a plate and allow them to rest for 2 minutes.

8. Warm the pizza sauce in a small saucepan or microwave until hot.

9. Place each burger on the bottom half of a bun. Spoon about 1 1/2 tablespoons of pizza sauce over the patty, add fresh basil and optional toppings, then close with the top bun and serve immediately.