01 - Preheat oven to 400°F. Line a baking sheet with parchment paper.
02 - In a skillet over medium heat, sauté diced onion until translucent, about 3 minutes. Add ground beef, garlic powder, salt, and black pepper. Cook while stirring until beef is fully browned, then drain excess fat.
03 - Stir in ketchup, yellow mustard, Worcestershire sauce, and chopped pickle if using. Remove mixture from heat and allow to cool slightly.
04 - Flatten each biscuit round. Spoon 1 tablespoon of beef mixture onto the center of each, followed by 1/2 tablespoon shredded cheddar cheese and a mozzarella cube on top.
05 - Wrap dough around the filling, pinching edges to fully seal and form a ball. Place seam-side down on prepared baking sheet.
06 - Brush each dough ball with beaten egg and sprinkle generously with sesame seeds.
07 - Bake in preheated oven for 15 to 18 minutes, or until biscuit exterior is golden brown.
08 - Allow cheeseburger bombs to cool slightly before serving. Offer with ketchup, mustard, or preferred burger sauces for dipping.