Place 8 ounces cream cheese in a large bowl and let sit out at room temperature to soften while you heat the oven and prep the peppers. Arrange a rack in the middle of the oven and heat the oven to 400°F. Line a rimmed baking sheet with parchment paper.

Halve 12 large jalapeño peppers lengthwise. If desired, scrape out the seeds and ribs with a small spoon and discard.

Shred 6 ounces sharp yellow cheddar cheese (about 1 1/2 cups). Add the cheddar, 3/4 teaspoon kosher salt, 1/2 teaspoon black pepper, 1/2 teaspoon garlic powder, and 1/4 teaspoon onion powder to the cream cheese and mix with a rubber spatula until well combined.

Divide the filling between the halved jalapeños (about 1 tablespoon per half). Use a butter knife to smooth the filling so it is flush with the tops of the peppers.

Cut 12 slices bacon in half crosswise. Wrap each jalapeño half in a piece of bacon so the ends are tucked under the pepper. Use a toothpick to secure the bacon in place by skewering it from side to side. Arrange the peppers cut-side up on the prepared baking sheet.

Bake until the bacon is crispy and the filling is melted and lightly browned, 25 to 30 minutes.

Let the peppers cool for 10 minutes before serving.