01 -
In a large skillet over medium-high heat, cook bacon until golden brown and crisp. Transfer to paper towels and set aside. Reserve all rendered bacon fat in the skillet for onion caramelization.
02 -
Peel and slice sweet onions into 0.6 cm thick rings and separate into layers. Add to the skillet with reserved bacon fat or olive oil. Season with 2 g kosher salt, 1.5 g black pepper, and optional crushed red pepper flakes. Stir well.
03 -
Cook onions over medium heat uncovered, stirring occasionally for 10 to 15 minutes until translucent and tender. Avoid rushing to deepen flavor.
04 -
Add Coca Cola to the skillet and continue cooking uncovered over medium-low heat for 20 to 30 minutes until onions become jammy, glossy, and brown with most liquid evaporated. Stir occasionally to prevent sticking.
05 -
In a bowl, gently combine ground beef, barbecue sauce, remaining salt and pepper, garlic powder, and onion powder until just mixed. Form six equal portions, flatten into patties, and press a shallow indentation in the center of each to prevent puffing. Chill until ready to grill.
06 -
Preheat grill to medium-high heat and lightly oil grates. Grill patties 5 to 8 minutes per side until desired doneness (minimum 74 °C internal temperature for well done). Place cheddar slices on patties during last minute to melt.
07 -
Spread butter on brioche buns and toast on grill or pan until golden and crisp to prevent sogginess.
08 -
Layer grilled patties on toasted buns. Add crispy bacon, tomato slices, lettuce, pickles, condiments of choice, and generous spoonfuls of caramelized Coca Cola onions. Cap with top bun and serve immediately.