01 - Combine flour, yeast, salt, and sugar in a large bowl. Stir in warm water and melted butter. Mix until a shaggy dough forms, then knead by hand or mixer for 5-7 minutes until smooth and elastic. Cover and let rest for 15 minutes.
02 - Cook ground beef and diced onion in a skillet over medium heat until beef is browned and onion is soft, approximately 5 minutes. Drain excess fat. Add salt, pepper, garlic powder, ketchup, mustard, and chopped pickles. Remove from heat and let cool slightly, then stir in shredded cheddar cheese.
03 - Preheat oven to 425°F. Line a baking sheet with parchment paper. Divide dough into 16 equal portions. Flatten each piece into a round disc. Place 1 tablespoon of filling in the center of each disc, pinch edges tightly to seal, and roll into smooth balls.
04 - Bring 6 cups of water to a boil in a large pot. Carefully stir in baking soda. Boil each dough ball for 20 seconds, then remove with a slotted spoon and place on the prepared baking sheet.
05 - Brush each bomb with beaten egg and sprinkle generously with coarse salt. Bake for 12-15 minutes until deep golden brown. Serve warm with additional ketchup or mustard for dipping.