Combine the flour, baking powder, baking soda and salt in a large bowl. Using a dough cutter, combine until the ingredients are incorporated. Scatter the cold butter pieces over the top of the flour mixture and continue to combine until the mixture resembles coarse meal. Add the buttermilk and mix just until the dough begins to come together.
Scrape the dough onto a lightly floured counter. Pat the dough into a 10 by 12-inch rectangle about 3/4-inch thick. Use a 3-inch round cutter to cut out the biscuits. Press together the scraps of dough and repeat the process. Place the biscuits on a baking sheet lined with parchment paper; brush the tops with cream and sprinkle with sugar. Bake the biscuits until lightly golden brown, 12 to 15 minutes. Remove from the oven and brush the tops with the remaining melted butter.