Preheat the oven to 425°F.
Place the gnocchi, bell peppers, zucchini, tomatoes, and red onion on a large sheet pan.
Drizzle with olive oil and sprinkle with salt, pepper, garlic powder, and paprika. Toss to coat evenly.
Add the sliced sausage and spread everything out into an even layer.
Roast for 20-25 minutes, stirring halfway through, until the vegetables are tender and the gnocchi is golden.
Top with Parmesan and parsley if desired before serving.