Preheat the oven to 400°F.
In a large mixing bowl, toss the trimmed asparagus with olive oil, garlic powder, salt, and black pepper until evenly coated.
Spread the asparagus in a single layer on a baking sheet lined with parchment paper.
Sprinkle the mozzarella and Parmesan cheese evenly over the asparagus. If using, add red pepper flakes for a bit of heat.
Bake in the preheated oven for 15-20 minutes, or until the asparagus is tender and the cheese is bubbly and golden brown.
Remove from the oven and drizzle with fresh lemon juice before serving.