In a large bowl, combine the ground chuck, Essentials Blend seasoning, Bootleg Burger seasoning, and beef powder. Mix until evenly incorporated, then fold in the shredded cheddar cheese and softened cream cheese.
Cut the tops and bottoms off the onions. Slice each onion halfway and carefully separate the layers to create onion cups.
Fill the larger onion halves with the meat mixture, placing about 1–2 tablespoons of cream cheese in the center if desired. Top with a matching onion half and press together to form a sealed onion bomb.
Wrap each onion bomb with 3–4 slices of bacon, securing the ends with toothpicks or skewers as needed.
Preheat your pellet grill to 275°F.
Season the outside of the bacon-wrapped onion bombs lightly with additional Bootleg Burger seasoning.
Place the onion bombs on the grill and cook for 1 hour 45 minutes to 2 hours, or until the bacon is crisp and the internal temperature of the beef reaches 160°F.
During the last 10–15 minutes of cooking, brush the onion bombs with the black cherry chipotle barbecue sauce and allow it to caramelize.
Remove from the grill, let rest for 5 minutes, then serve warm.