First, preheat your oven to 375°F (190°C) and line a baking sheet with parchment paper. This prevents the peppers from sticking and makes cleanup a breeze. While the oven heats up, wash the mini peppers, slice them in half lengthwise, and carefully remove the seeds and white membranes.
In a medium-sized mixing bowl, combine the softened cream cheese, shredded cheddar cheese, garlic powder, onion powder, salt, and pepper. Use a spatula or fork to mix everything together until the filling is smooth and well-combined. Make sure there are no large lumps of cream cheese.
Now it's time to fill the pepper halves. You can use a small spoon to carefully scoop the cream cheese mixture into each pepper half. For a cleaner look, you can transfer the filling to a piping bag (or a zip-top bag with the corner snipped off) and pipe it neatly into the peppers.
Arrange the stuffed peppers in a single layer on the prepared baking sheet. Place the sheet in the preheated oven and bake for 12-15 minutes. You'll know they're ready when the peppers are tender-crisp and the cheese filling is hot, bubbly, and slightly golden on top.
Once baked, carefully remove the peppers from the oven and let them cool for a few minutes, as the filling will be very hot. Just before serving, sprinkle the freshly chopped chives over the top for a touch of color and fresh flavor. Serve them warm and watch them disappear!