In a large bowl, combine olive oil, maple syrup, dijon mustard, garlic powder, onion powder, salt, and pepper. Stir to combine, then add halved Brussels sprouts and stir well, making sure that everything is evenly coated.
2 Tbsp Olive Oil, 2 Tbsp Maple Syrup, 2 Tbsp Dijon Mustard, ¾ tsp Garlic Powder, ¾ tsp Onion Powder, ½ tsp Kosher Salt, Black Pepper, 1 Pound Brussels Sprouts, trimmed and sliced in half