Preheat your oven to 400°F (200°C).
Line a baking sheet with parchment paper or lightly grease it.
In a large mixing bowl, combine the softened cream cheese, drained pimentos, garlic powder, kosher salt, cayenne pepper, and 1 cup of shredded cheddar cheese.
Stir until the filling is smooth and evenly combined.
Wash the mini sweet peppers and pat dry.
Slice each pepper in half lengthwise.
Remove the seeds and membranes from each pepper half.
Spoon approximately 1 tablespoon of the pimento cheese mixture into each pepper half.
Arrange the stuffed peppers cut-side up on the prepared baking sheet.
Sprinkle the remaining ¾ cup shredded cheddar cheese evenly over the tops.
Bake for 10 to 12 minutes or until the cheese is melted and bubbly.
Remove from the oven and allow the peppers to cool for about 10 minutes.
Garnish with freshly sliced chives before serving.