Pre-heat oven to 375°F and line a large, rimmed baking sheet with a piece of parchment paper or a silicone baking mat. Set aside.
In a medium mixing bowl, combine cream cheese, cheddar cheese, and garlic powder. Season with salt and black pepper, to taste, and stir to combine.
Fill each jalapeño half with some of the cheese mixture and wrap with one-half slice bacon. Secure bacon with a toothpick and set on the prepared baking sheet.
Place the baking sheet in the pre-heated oven and bake until the cheese mixture is golden-brown and bubbly, and the bacon is cooked through, approximately 20-25 minutes. Rotate the baking sheet once halfway through cooking to ensure even browning.
Remove the baking sheet from the oven and transfer the poppers to a serving platter. Garnish with fresh chopped parsley and serve immediately.