Heat oven to 475 degrees. Line a baking sheet with parchment paper or a silicone liner.
In a large bowl, whisk together dry ingredients.
Add the melted butter to the buttermilk and stir until small clumps form.
Combine the buttermilk mixture and dry ingredients with a rubber spatula, until just incorporated and the dough starts to slightly pull away from the bowl.
Using a greased ¼-cup measure, scoop out mounds of the dough and drop them onto the prepared baking sheet.
Bake the biscuits until the tops are golden brown and crisp, 12 to 14 minutes.
Top with additional melted butter if desired. Serve warm.