Gather the ingredients.
Preheat the oven to 425 F and line a large baking sheet with parchment paper. Prepare an ice bath in a large bowl.
Blanch the Brussels sprouts by bringing a large pot of salted water to a boil. Add Brussels sprouts and cook until bright green and very tender, about 8 minutes.
Transfer the Brussels sprouts to the prepared ice bath to cool, then drain onto a paper towel-lined plate.
On the large baking sheet, toss the blanched Brussels sprouts with oil, minced garlic, thyme, and basil.
Using the end of a small glass or mason jar, press down on the Brussels sprouts to smash them into a flat patty.
Season each smashed Brussels sprout with salt and pepper, then sprinkle parmesan on top.
Bake until the bottoms of the sprouts are crispy and the cheese is melty and golden, 15 to 20 minutes.
Garnish with parsley and serve warm.
