Patty Melts with Secret Sauce 🍔

 Ingredients:
For the Patty Melts:
1 lb. Ground beef
6 slices rye bread
½ tsp. Onion powder
½ tsp. Garlic powder
Salt and pepper to taste
6 slices cheddar cheese
6 slices provolone cheese
6 Tbsp. Butter, softened and unsalted
For the Secret Sauce:
¼ cup Mayonnaise
2 Tbsp. Chopped bacon pieces
3 Tbsp. Ketchup
1 tsp. Sugar
1 tsp. Relish