Preheat your oven to 420°F (215°C). Line a large rimmed baking sheet with parchment paper for easy release.

Bring a large pot of water to a boil. Add broccoli florets and 1 tsp salt. Blanch for 1 to 2 minutes until bright green but still firm. Immediately drain and transfer to a plate lined with paper towels, blotting thoroughly to remove excess moisture.

Sprinkle a thin, even layer of shredded parmesan cheese across the prepared baking sheet. Place the damp broccoli florets on top, leaving enough space between them to press down later.

Using the bottom of a small glass or shot glass, gently but firmly press each broccoli floret down to smash it slightly, creating a flat surface. Make sure each piece stays on the cheese layer.

Sprinkle the tops with additional parmesan cheese, salt, garlic powder, onion powder, and a pinch of cayenne pepper (if using). This adds flavor and improves crispiness.

Bake for 30 to 35 minutes, rotating the pan halfway through, until the cheese is golden brown and the edges are crispy. The broccoli should be tender but slightly crunchy on the ends.

Allow to cool on the baking sheet for 5 minutes before gently breaking apart. Serve warm with dip on the side.

In a small bowl, whisk together mayonnaise, buttermilk, Sriracha, rice vinegar, chives, garlic powder, and onion powder until smooth. Taste and adjust seasoning if needed. Chill until ready to serve.