01 - Preheat oven to 400°F. Line a baking sheet with parchment paper.
02 - Heat a skillet over medium heat. Sauté diced onion until translucent, about 3 minutes. Add ground beef, garlic powder, salt, and black pepper. Cook, breaking up meat, until browned through. Drain excess fat.
03 - Stir ketchup, yellow mustard, Worcestershire sauce, and chopped pickles into the cooked beef mixture. Remove from heat and set aside to cool slightly.
04 - Flatten each biscuit round on a work surface. Place 1 tablespoon of the beef mixture and 1/2 tablespoon shredded cheddar in the center. Top with a mozzarella cube.
05 - Wrap dough around the filling, pinching edges tightly to seal and forming a ball. Arrange each bomb seam-side down on the prepared baking sheet.
06 - Brush each bomb with beaten egg. Sprinkle sesame seeds on top.
07 - Bake in the preheated oven for 15 to 18 minutes, until the biscuit dough is puffed and golden brown.
08 - Allow baked bombs to rest a few minutes before serving. Offer with additional ketchup, mustard, or preferred burger sauces.