Prepare your grill for direct cooking. If using charcoal light it now.

Place all ingredients for the burger patties in a large bowl. Mix with your hands until just combined. Careful not to over work or you can end up with dense, tough burgers.

Form mixture into 6 equal sized patties, again careful to not over work. Place on a plate. Set aside. Tip: when shaping patties form a depression in the center so edges are slightly thicker. This prevents the "bulge effect" when cooking.

Combine all ingredients for the basting sauce in a small bowl. Combine brown sugar and cinnamon for the pineapple rings in a separate small bowl. Set both aside.

Drain can of pineapple. Lay pineapple rings out in a single layer on paper towels. Blot tops with additional paper towels. Transfer to a large plate/platter in a single layer. Just before grilling, sprinkle half of brown sugar mixture on pineapple rings, flip and sprinkle second side with remaining mixture.

For medium cooked burgers: Grill 5 minutes on first side. Flip, brush cooked side with basting sauce. Grill another 5 minutes. Flip basted side down, brush second side with sauce. Cook 2-3 minutes. Flip one last time place one slice of cheese on each patty. Cook 2-3 minutes more. Transfer burgers to a large platter in a single layer. Cover with foil to keep warm, set aside.

Place prepared pineapple rings on grill. Cook 2-5 minutes per side, or until sugar starts to caramelize. Place at least one ring on each burger patty.

To Assemble: toast buns if desired. Spread garlic pepper aioli on top and bottom bun. Place lettuce then tomato on bottom bun. Place burger patty topped with pineapple. Add crispy onions and/or additional sauce if desired. Place top bun. Enjoy!