Preheat your oven to 375°F (190°C).
In a large mixing bowl, combine ground beef, chopped mushrooms, shredded cheddar cheese, breadcrumbs, BBQ sauce, egg, Worcestershire sauce, garlic powder, salt, and black pepper.
Shape the mixture into mini meatloaves, about 2 inches wide and 4 inches long, placing them on a lined baking sheet.
Brush additional BBQ sauce on top of each mini meatloaf for added flavor.
Bake in the preheated oven for 25-30 minutes, or until the internal temperature reaches 160°F (71°C).
Remove from the oven and let them rest for 5-10 minutes before serving.