Preheat the oven to 375 degrees and line a baking sheet with parchment paper.
Slice the tops off each mini pepper and remove the seeds and membranes. Use a small knife to carve simple jack-o'-lantern faces on one side of each pepper.
Place the carved peppers on the prepared baking sheet.
In a mixing bowl, combine the cream cheese, cheddar cheese, garlic powder, salt, and black pepper until evenly mixed.
Spoon the cheese mixture into each carved pepper, filling them to the top without overstuffing.
Bake for 15 to 18 minutes until the peppers soften slightly and the filling is hot and bubbly.
Remove from the oven and let cool for a few minutes before serving.