Cook smash burgers to your preferred temperature. Stack a patty on the bun and add a slice of Gouda. Stack the second patty and second slice of Gouda.
Spoon 2 tablespoons of the blueberry ale BBQ sauce over the patties. Add leaves of fresh spinach and top with a generous pinch of crispy onion petals and salt and pepper to taste.
Repeat with second burger. Add a ramekin of extra BBQ sauce for fry dipping!