Mix 2 teaspoons of the sugar, the yeast and 1/4 cup warm water (around 115 degrees F) in a large bowl and let bloom for 30 minutes.
Whisk together the flour, baking powder, baking soda, salt and the remaining 2 teaspoons sugar. Add the yeast mixture, buttermilk and butter to the dry ingredients and stir with your hands to just combine, being careful not to overwork the dough. Cover and let rest in a warm area to rise, 30 to 40 minutes.
Preheat the oven to 425 degrees F. Butter a baking sheet.
Place the dough on a floured surface and knead until smooth. Roll out to 3/4 inch thick, and cut out biscuits with a biscuit cutter. (We use a 2 1/2-inch cutter.) Place the biscuits on the buttered baking sheet nestled together, and brush the tops with melted butter. Allow to rest and rise for 15 minutes.
Bake until the tops are golden brown, about 8 minutes. Remove from the oven and brush immediately with more butter. Serve with your favorite jam or sausage gravy.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.