Preheat the oven to 425°F and line a large baking sheet with parchment paper or foil.
Place the sausages, halved baby potatoes, broccoli florets, and sliced red bell pepper on the baking sheet.
Drizzle the olive oil over everything, then sprinkle with garlic powder, oregano, salt, and black pepper. Toss to coat evenly.
Spread the ingredients in a single layer and bake for 25 to 30 minutes, turning the sausages and stirring the vegetables halfway through.
Remove the pan from the oven. Place one mozzarella ball on top of each sausage.
Slice each black olive in half and set one half on each mozzarella ball to create the eyeball effect. Serve right away.