Cook bacon on medium heat in large skillet until lightly browned. Transfer cooked bacon to paper towel lined plate to drain. Set aside.
Pour off bacon fat, leaving 1 1/2 tablespoons in skillet. Place garlic and onions in skillet and cook over medium heat until onions are tender and clear. Add brown sugar, cumin, cayenne, coffee, vinegar, and maple syrup to onion / garlic mixture. Bring to boil. Stir in bacon pieces and remove from heat.
Pour mixture into slow cooker and cook, uncovered, on high setting for 6 1/2 hours or until liquid forms a syrup. Transfer to food processor or blender and pulse until it reaches the desired consistency.
Let cool completely and store in an airtight container for up to four weeks in the refrigerator.
Adapted from : Martha StewartNutrition information is for 1 tablespoon.