Preheat the oven to 400°F. Line a rimmed baking sheet with parchment paper.
Halve 12 large jalapeño peppers lengthwise. Remove seeds and ribs with a pairing knife.
Mix cream cheese, shredded cheddar cheese, garlic salt and a large pinch of pepper together with until well combined.
Fill each jalapeño half with cheese mixture, then smooth with a knife so it is even with the edge of each pepper.
Cut each bacon slice in half, crosswise then wrap each cheese-filled pepper half with bacon and secure with a toothpick.
Arrange the peppers cut side up on the prepared baking sheet and bake for 25 to 30 minutes, until the bacon is crispy, and the filling is melted and lightly browned.
