Step 1: Cook the ground beef in a large skillet over medium-high heat until browned, breaking it up with a spoon. Drain off any excess grease thoroughly.
Step 2: In the same skillet or a separate pan, cook the bacon until crispy. Crumble the cooked bacon and set aside.
Step 3: In a medium bowl, combine the drained ground beef, crumbled bacon, shredded cheddar cheese, finely chopped onion (if using), garlic powder, salt, and black pepper. Mix well to ensure all ingredients are evenly distributed.
Step 4: Unroll the crescent roll dough and separate it into 16 triangles.
Step 5: Take one mozzarella string cheese stick and place it at the wider end of a crescent roll triangle. Spoon a small amount (about 1-2 tablespoons) of the beef and bacon mixture over and around the mozzarella stick.
Step 6: Carefully roll up the crescent dough, starting from the wide end, enclosing the filling. Pinch and seal the edges tightly to prevent any cheese from leaking out during frying.
Step 7: Set up a breading station: one shallow dish with the beaten egg and another with the panko breadcrumbs. Dip each assembled bomb first into the beaten egg, allowing excess to drip off, then dredge thoroughly in the panko breadcrumbs, pressing gently to coat evenly.
Step 8: Heat vegetable oil in a large, heavy-bottomed pot or deep fryer to 350°F (175°C).
Step 9: Carefully place a few bombs into the hot oil, making sure not to overcrowd the pot. Fry for 3-5 minutes, turning occasionally, until golden brown and crispy, and the cheese is melted and gooey.
Step 10: Remove the bombs with a slotted spoon and transfer them to a plate lined with paper towels to drain excess oil.
Step 11: Serve immediately with your favorite dipping sauces like ketchup, mustard, ranch dressing, or a special burger sauce. Enjoy!