Heat a large skillet over medium heat. When hot, add the deer bacon pieces. Cook for about 5 minutes, stirring occasionally, until the bacon is crispy. Remove the bacon from the skillet and transfer onto a paper towel-lined plate.
Place an oven rack in the center of the oven and preheat the oven to 400 degrees F.
In a medium bowl, combine the cream cheese, cheddar cheese, and half of the chopped bacon. Use a fork or spoon to mash the mixture until everything is well combined.
Slice the jalapenos in half lengthwise (I recommend wearing kitchen gloves for this) and use a spoon to scrape out the seeds and white membranes. Discard.
Stuff each jalapeno half with enough cream cheese mixture to sit level with the sides. Don't be tempted to overstuff them! Arrange the stuffed peppers in a single layer on a rimmed baking sheet lined with parchment paper.
In another medium bowl, combine the panko breadcrumbs with the butter and stir until the crumbs are moistened. Stir in the remaining half of the chopped deer bacon and top each jalapeno popper with about 1 teaspoon of the crumb mixture.
Bake for about 15 minutes, until the peppers are tender and the breadcrumb topping is golden brown in spots. Let the poppers cool for 5 minutes before serving.