01 - Preheat the oven to 400°F. Line a baking sheet with parchment paper.
02 - In a skillet over medium heat, cook the diced onion for about 3 minutes until translucent. Add the ground beef, garlic powder, salt, and black pepper and cook until the meat is well browned. Drain any excess fat.
03 - Mix ketchup, yellow mustard, Worcestershire sauce, and chopped pickles into the browned beef. Remove from heat and allow the filling to cool slightly.
04 - Flatten each biscuit round. Place 1 tablespoon beef mixture and 1/2 tablespoon shredded cheddar in the center, then top with a mozzarella cheese cube.
05 - Fold the dough around the fillings, pinching the seams to enclose fully and form a ball. Place seam side down on the prepared baking sheet.
06 - Brush each dough ball with beaten egg and sprinkle with sesame seeds.
07 - Bake in the preheated oven for 15 to 18 minutes, or until the pastry turns golden brown.
08 - Let the cheeseburger bombs cool slightly before serving. Pair with extra burger sauces for dipping if desired.