Prepare the grill by cleaning the grill grates and preheating to medium heat, around 400°F.

In a bowl, whisk together the egg, half of the cola, crushed saltines, French dressing, diced onion, minced garlic, and Parmesan until combined.

Add the ground beef to the mixture and gently combine. Shape into six equal patties.

In a separate bowl, mix the remaining cola with a bit of French dressing for brushing.

Grill the patties for 5-6 minutes on each side until well browned and internal temperature reaches 165°F.

Brush the cola mixture onto the burgers just before flipping.

Let the burgers rest for a couple of minutes before serving on brioche buns.