In a large bowl, combine shrimp, olive oil, minced garlic, onion powder, lemon juice, paprika, salt, pepper, and red pepper flakes if using. Toss to coat the shrimp evenly.
Place the shrimp in a single layer on a baking sheet lined with parchment paper. Sprinkle with Parmesan cheese.
Bake in the preheated oven for 9-10 minutes or until the shrimp are pink and opaque.
Remove from oven, garnish with chopped parsley, and serve immediately.