Preheat the oven to 425 F. Cut the butter into cubes and transfer to the freezer while you get everything else ready.
Add the flour, baking powder, sugar, and salt to a bowl and stir to combine. Add the cubed butter and toss so each piece is covered in flour (this will help the butter to not melt as quickly).
Take each cube of butter, one at a time, and break it into smaller pieces, about pea sized. Repeat with the remaining cubes of butter, making sure to toss the broken pieces of flour each time.
Add the cheddar, chives, garlic powder, and black pepper. Toss until it is combined, then add the buttermilk. Stir with a rubber spatula or your hand until the dough just comes together. It should be very shaggy.
Dump the dough out onto the table and shape into a rectangle, about 1 inch thick. Cut out 8 biscuits and transfer them to a lined baking sheet. Transfer the biscuits to the oven and let them bake for 12-15 minutes, until starting to brown.
Once the biscuits are out of the oven, brush on a little melted butter, crack some black pepper on top and enjoy!