Step 1

Preheat oven to 350 degrees F. Coat a 9- x 13-inch baking dish with cooking spray.

Step 2

In a large skillet over medium-high heat, cook ground beef and onion 5 to 7 minutes, or until browned; drain excess liquid. Add garlic powder, salt, pepper, ketchup, and 2 tablespoons mustard; mix well and heat 2 minutes.

Step 3

Place bottom half of buns in baking dish. Top with beef mixture, pickle chips, and cheese. Place top half of buns over cheese.

Step 4

In a small saucepan over low heat, combine butter, brown sugar, Worcestershire sauce, sesame seeds, and remaining 1 tablespoon mustard. Heat 3 to 5 minutes, or until sauce is smooth, stirring occasionally. Pour sauce over buns, then cover with foil.

Step 5

Bake 15 to 20 minutes, or until heated through and cheese is melted.