Cook bacon on medium high until bacon is browned, then drain off all of the grease and set the bacon aside.  (I use an iron skillet)

Cook onions and garlic in same pan as the bacon on medium high until onions are gently caramelized.  

Add bacon, coffee,  maple syrup, brown sugar, chili powder, cayenne pepper, and apple cider vinegar to the onion mixture.

Turn down to medium low and let simmer for 45 minutes while stirring occasionally.