Put the chopped bacon into a skillet and cook over medium-high heat until crispy, 10 to 15 minutes. Stir frequently to make sure the pieces are evenly cooked.
Transfer the bacon bits to a paper-towel lined plate and crumble any larger pieces. Transfer any excess bacon fat to a heatproof bowl (see my recipe tips for suggestions!) until only a thin layer coats the bottom of the skillet.
Add the onions to the pan and cook over medium heat until softened and starting to brown, about 5 minutes. Add the garlic and saute for one minute, until the garlic is softened.
Add the coffee, brown sugar, apple cider vinegar, and maple syrup. Bring the mixture to a simmer, using a wooden spoon to scrape up any browned bits from the bottom of the pan.
Add the bacon back to the pan and continue to simmer, reducing the heat if needed, until the liquid evaporates and the mixture becomes thick and sticky, about 30 minutes.
Stir occasionally to prevent sticking. You’ll know when it’s done when there’s only a thick syrup left around the bacon. I like to drag my spatula along the bottom of the pan, and if the mixture doesn’t run back in immediately, the jam is done.
Transfer the jam to an airtight container and store in the refrigerator. If you like, you can put the mixture in the food processor and make it more of a jam consistency, but I prefer mine on the chunkier side.