Preheat the oven to 375°F. Spritz a standard size baking sheet with cooking spray. Hollow the mushroom caps removing the stem.
In a medium skillet cook the bacon over medium high heat until crisp. Remove from pan reserve 3 Tbsp drippings.
Add the diced onion and ground beef to the drippings. Season with salt and black pepper. Add Worcestershire sauce. (Adjust salt according to BBQ seasoning used)
Cook until no pink remains then drain fat from pan. Add minced garlic. Continue to cook until the garlic is fragrant around 1-2 minutes.
To the skillet add cream cheese, barbecue sauce, dill pickles, barbecue seasoning and mustard. Cook until cream cheese has melted and ingredients are evenly distributed.
Remove from the heat. Add 1 cup shredded cheddar cheese. Mix well.
Divide filling among mushroom caps and top with remaining shredded cheese.
Bake for 16-18 minutes until the cheese has melted and the mushrooms have softened. Serve immediately.
Notes
Mushrooms - You can use any mushroom variety that you enjoy for these cheese stuffed mushrooms. Depending on the type of mushroom, the size varies. The mushroom caps used in this recipe, were purchased at my local Costco, and they are were large jumbo-size mushrooms so the amount of fillingreflects this. If you use a smaller variety of mushrooms, you'll have ample cheeseburger filling to make more than 30, so have extra mushrooms on hand just in case.
Bell Peppers - The stuffing for these mushrooms is also delicious mushroom bbq bacon cheeseburger stuffed peppers, too! You can use mini peppers or full size peppers cut in half.
Protein - You can make the cheeseburger filling using ground turkey or ground chicken.
BBQ Sauce - I recommend using a thick barbecue sauce in the filling so it doesn't become watery while baking. You can replace the barbecue sauce with ketchup.
Freeze Extra Filling - Depending on the size of the mushrooms, the yield may be greater. Extra filling, can be frozen if needed.
Drain on Paper Towels - The mushrooms will naturally release liquid while baking. Carefully transfer them to a paper towel to blot and then arrange on a serving platter