InstructionsReset

1. Place a rack in middle of oven; preheat to 350°. Generously coat a 13x9" baking dish with nonstick vegetable oil spray. Cook 4 oz. bacon (4–6 slices) in a dry large skillet, preferably nonstick, over medium heat, turning occasionally, until browned and crisp, 8–10 minutes; transfer to paper towels to drain. Let sit until cool enough to handle, then finely chop.
2. Whisk one 8.5-oz. box corn muffin mix and 2 cups half-and-half in a medium bowl until smooth. Add 6 large eggs and 2 tsp. Diamond Crystal or 1 1/4 tsp. Morton kosher salt and whisk to combine. Stir in bacon, 1/2 cup coarsely grated extra-sharp cheddar, 1/2 cup chopped drained pickled jalapeños, patted dry, and 2 Tbsp. finely chopped chives; scrape batter into prepared pan.

3. Bake casserole until slightly puffed and just set (center should still wobble slightly when casserole is gently shaken), 25–30 minutes. Let cool 10–15 minutes before cutting into squares. Do Ahead: Casserole can be baked 5 days ahead. Let cool, cover, and chill.