Follow the steps in order for the best result.
Preheat your oven to 400 degrees Fahrenheit. Ensure you have 10 standard-size muffin cups/tins ready and ungreased.
In a large skillet, brown the ground beef along with the chopped onion, minced garlic, celery, and green bell pepper. Cook for approximately 6-8 minutes, or until the beef is no longer pink. Be sure to drain off any excess fat. Season generously with salt and pepper according to your preference.
Stir in your favorite barbecue sauce, and let the mixture simmer for about 5 minutes, stirring occasionally to ensure even flavor distribution.
While the beef mixture simmers, take each biscuit and place it into the ungreased muffin tins. Firmly press the dough down onto the bottom and up the sides of each cup, creating a well for the filling.
Spoon approximately 1/4 cup of the savory beef mixture into each biscuit cup.
Sprinkle the tops of each cup with grated parmesan cheese, then bake in the preheated oven for about 10-12 minutes, or until the biscuit edges are beautifully golden brown.
Remove the muffin tin from the oven and generously sprinkle grated cheddar cheese over the top of each biscuit cup. Return the tin to the oven for just 1-2 minutes, or until the cheddar cheese is perfectly melted and gooey.
Allow the Sloppy Joe Biscuit Cups to stand for about a minute before carefully loosening the edges of the biscuits and removing them from the pan. Serve warm and enjoy!