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 tablespoon Olive Oil, 2 tablespoon Maple Syrup, 2 tablespoon Dijon Mustard, ¾ teaspoon Garlic Powder, ¾ teaspoon Onion Powder, ½ teaspoon Kosher Salt, Black Pepper, 1 Pound Brussels Sprouts, trimmed and sliced in half