Cook the bacon in a skillet over medium heat until crispy, about 5 minutes. Remove to a cutting board, reserving 2 tablespoons of the bacon fat in the skillet. Chop the bacon into small pieces, then put them back in the skillet.
Put the bacon skillet over medium-high heat, add the brown sugar, molasses, honey, cider vinegar, sherry, garlic powder, mustard powder, shallots and garlic and bring the mixture to a slight boil. Reduce to a simmer and simmer until syrupy, 30 to 45 minutes. Let cool, then transfer to a canning jar and refrigerate. Enjoy within 2 days.