Preheat the oven to 400 degrees F (200 degrees C).
Place bacon in a large oven-proof skillet and cook over medium-high heat, turning occasionally, until evenly browned, about 5 minutes. Drain on paper towels.
Add Brussels sprouts to the same skillet. Cook over medium-high heat for 1 to 2 minutes.
Transfer skillet to the preheated oven. Bake until Brussels sprouts soften, about 20 minutes. Remove skillet carefully from the oven and stir in bacon. Continue baking until crispy, about 10 minutes more.
Mix mustard, maple syrup, and sriracha sauce together in a small bowl. Pour over Brussels sprouts-bacon mixture; stir to combine. Season with salt and pepper. Serve hot.
