Stuffed Brussels Sprouts

Preheat oven to 400º. Grease a large baking sheet with cooking spray. In a large pot of salted boiling water, blanch Brussels sprouts until bright green, 2 minutes. Rinse under cold water, then drain. Using a small spoon, scoop out insides of sprouts (reserve for another use), then transfer hollowed sprouts to a prepared baking sheet. In a medium bowl, stir together ricotta, Parmesan, bread crumbs, lemon zest, and red pepper flakes, and season with salt and pepper. Spoon mixture into Brussels sprouts, drizzle with olive oil, and sprinkle with more Parmesan. Bake until ricotta mixture is warmed through and Brussels sprouts are crispy, 20 to 25 minutes.