Preheat the oven to 375F/190C degrees. Line two baking sheets with parchment paper.
In a food processor, process flour, sugar, baking powder, garlic powder, salt and paprika to combine. Add the 1/2 cup cubed butter and process until the mixture looks like breadcrumbs. Empty into a large bowl.
Stir in 1 1/2 cups/170 g of the cheese and chives into the flour mixture. Make a well in the center of the bowl. In a liquid measuring cup or in a small bowl with a spout, whisk the buttermilk and egg until well combined. Pour the mixture into the medium bowl and, using a wooden spoon, stir until the mixture is combined. Near the end, you may have to fold it over itself a few times in the bowl to make sure it’s uniformly combined. (Resist the urge to use your hands so that the mixture doesn’t get too soft or compressed.)
Scoop the dough into 12 even portions (about 1/2 cup/80 grams each) onto the prepared sheet pan. Stagger the biscuits on the baking sheets. (You should have 6 biscuits per sheet pan.)
Brush each biscuit with the melted butter (you won’t use it all) and divide the remaining shredded cheese among the tops of the biscuits (about 2 teaspoons per biscuit).
Transfer to the oven and bake the biscuits for 15 minutes, then brush each biscuit with butter again, and rotate the pans between the oven racks. Continue to bake until the biscuits are light golden and the cheese on top is deeply golden, 5 to 10 minutes more. The biscuits should spring back gently when touched in the center.
Brush the finished biscuits generously with the remaining butter. Cool at least 10 minutes before serving warm (or cool completely and serve at room temperature).
If using dehydrated chives, use half the amount called for for fresh