Preheat the oven to 425 degrees F (218 degrees C). Line a baking sheet with parchment paper and set aside.

Fill a large pot with a couple inches of water and bring it to a boil.

In a measuring cup or bowl, whisk together the olive oil, lemon zest, garlic powder, pepper, and salt.

Place a steamer basket into the pot over the boiling water. Put the broccoli florets in the basket, cover, and cook for 5 to 7 minutes, checking for fork-tenderness at 5 minutes.

Remove the basket from the pot. Brush a layer of the olive oil mixture onto the parchment paper on the baking sheet.

Transfer the steamed broccoli to the parchment and spread out in a single layer. Using the back of a glass, smash each floret until flattened.

Brush the rest of the olive oil mixture on top of each floret. Sprinkle each one with parmesan cheese.

Bake until the cheese is crispy and the broccoli is crispy on the outside but remains tender on the inside, about 15 to 20 minutes.