Prepare a charcoal grill while you allow your patties to come to room-temperature.
When your coals are white, liberally season your burger patties with salt and place them on the hot grill. Grill for 5 minutes on each side for medium-rare.
Add the cheese to the patties in the last minute of cooking and allow the patties to rest while you heat the buns.
Heat the brioche buns on the grill. Buns will cook quickly on a hot grill, so keep an eye on them. You want a small amount of char on the bread and for the bun to get nice and toasted.
In a heavy-bottomed sauce pan caramelize the minced bacon on medium-low heat until it is golden brown. Don’t crisp it all the way. It’s nice to have it slightly chewy in the final product.
When the bacon is browned remove the bacon from the pan and drain all but about 2 tablespoons of the rendered bacon fat.
Sauté the onions and apple in the saucepan until they are caramelized.
Add the remaining ingredients and mix well to incorporate.
Reduce until the liquid has evaporated and the mixture has the texture of a thick compote or jam.
Add the bacon back to the mixture and combine.
Store Bacon and Cider Marmalade in refrigerator for up to 2 weeks in an airtight container.