Cook the bacon pieces in a large skillet over medium-high heat until crispy. Remove from the skillet and place on a paper towel-lined plate. Chop into small bits.
Remove all but 2 tablespoons of bacon grease from the skillet and reduce the heat to medium.
Add the onion and cook for 5 minutes, stirring occasionally.
Add the shallot and cook, stirring often, for another 10-15 minutes, or until caramelized.
Add the minced garlic and chili powder, then cook, stirring constantly, for 1 minute.
Add the brown sugar, vinegar, maple syrup, bacon bits, and a small pinch of salt.
Simmer, stirring frequently, for 10 minutes or until the mixture thickens.
Serve warm or at room temperature.
Store in an airtight jar in the refrigerator. Enjoy.