Cook bacon in a saucepan over medium heat until crisp and fat is rendered. Move bacon to a paper towel lined plate.
Measure 1/4 cup of fat, and discard remaining. If you don't have enough, add olive oil to equal 1/4 cup.
Add shallot and garlic, and saute until fragrant, about 3 minutes.
Whisk in red wine vinegar, brown sugar, pepper, and mustard powder. If you prefer more acidity, add an extra tablespoon of brown sugar and red wine vinegar.
Stir in reserved bacon, and serve over salad immediately.