Preheat oven to 400F.
In a food processor or a mixer, mix all the ingredients for the burgers together except for the coconut oil.
Form 6 burgers with your hands, apply some oil on your fingers to prevent the mixture to sticking.
Lay the burgers on a greased cookie sheet and pour 1 small drop of coconut oil on each burger.
Bake for 15 minutes at 400F, and then set on broil for 2 additional minutes. Remove from the oven and set aside.
While the burgers are baking, prepare the onions.
Heat up a small sauce pan and melt the remaining coconut oil along with the apple cider vinegar, cinnamon and the sugar. Add the chopped onion and let it cook on medium high heat for 6 minutes.
Stir a few times in the process.
When the burgers are ready, grill some buns and then spread some coconut oil on the hot buns and follow with one patty, and then a bunch of caramelized onions, fresh tomatoes and lettuce.