Prepare three 6-inch cake molds and spray them with cooking spray.

Heat the olive oil and butter in a skillet over medium heat. Add the onion and jalapeños and cook for 5–6 minutes. Transfer to a bowl.

Arrange bacon inside each cake mold, starting in the center and allowing half of each strip to hang over the edge.

Season with beef seasoning, then add a ½-inch layer of ground brisket.

Add the cooked onions, jalapeños, and pepper Jack cheese.

Add another ½-inch layer of ground brisket and season with additional beef seasoning.

Fold the bacon over the top to completely wrap the burger. Repeat with the remaining two molds.

Turn the molds onto a wire cooking rack and gently remove the molds.

Preheat the smoker to 275°F using hickory wood.

Smoke for 30–45 minutes. Brush with BBQ sauce and flip.

Continue smoking until the burgers reach 160°F internally.

Brush the tops with additional BBQ sauce and add the American cheese. Close the smoker and cook for about 4 minutes, until the cheese melts.

Spread mayonnaise on the sourdough bread and toast it on the grill.

Remove the burgers when they reach 165°F internally and rest for about 6 minutes.

Add BBQ sauce to the toasted bread, add the Boss Burger, and serve.