Arrange a rack in the middle of the oven and heat the oven to 425°F.
Trim the bottoms from 1 pound Brussels sprouts if they appear dry or yellowed, and peel away the loose outer leaves. Halve each Brussels sprout through the stem.
Place the Brussels sprouts on a rimmed baking sheet. Drizzle with 2 tablespoons olive oil and 1 tablespoon of the chili crisp. Season with ½ teaspoon kosher salt and toss with your hands until evenly coated. Arrange cut-side down in a single layer.
Roast for 10 minutes, stirring halfway through.
Meanwhile, finely grate the zest of 1 medium lemon into a small bowl (about 1 teaspoon). Finely grate 1 ½ ounces Parmesan cheese (scant ½ cup), or measure out ⅓ cup store-bought grated, and add to the bowl. Add the remaining 1 tablespoon chili crisp and ⅓ cup panko breadcrumbs, and stir to combine. Cut the zested lemon into quarters.
Remove the baking sheet from the oven. Sprinkle evenly with the panko mixture and toss with a spatula until evenly coated. Spread back into a single layer.
Return to the oven and roast until the Brussels sprouts are tender and the leaves and panko are browned and crisp, 6 to 8 minutes.
Squeeze the juice of 1 lemon quarter over the sprouts. Serve with the remaining lemon quarters if desired.
