Step 1

Preheat oven to 450°F. Fill a large bowl with ice water. Bring a large saucepan of water to a boil over medium-high heat. Add Brussels sprouts and cook just until tender when pierced with a fork, about 10 minutes. Drain the sprouts and transfer to the prepared ice bath. Let stand until cool enough to handle, about 5 minutes. Drain well and transfer to a clean kitchen towel. Pat dry completely and place in a large heatproof bowl; set aside.

Step 2

Meanwhile, heat a large skillet over medium heat. Add bacon and cook, stirring occasionally, until the fat has completely rendered and the bacon bits are very crispy, 7 to 10 minutes. Remove the bacon with a slotted spoon to a paper-towel-lined plate. Pour the bacon drippings over the sprouts and toss to fully coat. Working with a few sprouts at a time, place the sprouts on a sturdy cutting board and crush with a mason jar or heavy flat-bottomed cup until they're about 1/2 inch thick and have cracked. Transfer to a large baking sheet.

Step 3

Drizzle the crushed sprouts with oil. Bake until the bottoms begin to turn golden-brown, 10 to 12 minutes. Remove from oven; flip the sprouts and sprinkle with Cheddar. Bake until the cheese has melted, 3 to 5 minutes. Sprinkle with pepper and salt. Using a spatula, transfer the sprouts to a serving platter, along with any crispy cheese on the pan; top with sour cream and the reserved bacon.