1. Prepare the Ingredients: Dice the onion, mince the garlic, and set them aside.

2. Make the Spice Rub: In a small bowl, combine the salt, pepper, onion powder, paprika, and chili powder.

3. Sauté the Onions: Heat a skillet or griddle over medium heat. Add the avocado oil and diced onions, cooking until soft and translucent (about 4-6 minutes).

4. Cook the Beef: Add the ground beef to the skillet with the onions, break it apart, and cook until browned. Sprinkle in the spice rub and mix well, cooking a bit more.

5. Add the Tomato Mix: Stir in the tomato sauce and tomato paste, cooking until well combined.

6. Add the Sauces: Mix in the ketchup, mustard, Worcestershire sauce, and BBQ sauce. Let the mixture cook until thickened (about 5-7 minutes). Remove from heat and keep warm.

7. Assemble the Sandwiches: On your brioche slices, layer mozzarella, then gouda, then a generous spoonful of the sloppy joe mixture, followed by more mozzarella and gouda, and top with another brioche slice.

8. Toast the Sandwiches: Clean the skillet if needed and return it to medium heat. Butter the outside of the sandwiches and place them in the skillet. Press gently with a spatula. Toast one side until golden brown (~2 minutes), then flip and toast the other side until golden and the cheese is melted.

9. Serve: Remove from the skillet, let rest briefly, then slice and serve.