In a large skillet, cook bacon over medium heat until crisp, 4 to 5 minutes. Remove bacon using a slotted spoon, and let drain on paper towels, reserving drippings in skillet. Add onion, and cook until beginning to brown, 2 to 3 minutes. Remove from pan, and let drain on paper towels.
In a large bowl, combine Brussels sprouts, bacon, onion, and pecans. In a medium bowl, whisk together vinegar, brown sugar, salt, mustard, zest, and red pepper. While whisking constantly, slowly add oil. Add dressing to Brussels sprouts mixture, and toss. Serve immediately.
Recipe by Louisiana Cookin' at https://louisianacookin.com/shredded-brussels-sprouts-bacon-salad/