To make the biscuits:

1. Preheat the oven to 450 degrees. Line a small baking sheet with parchment paper and set aside. 
2. In a large bowl, stir to combine the flour, 3 tablespoons sugar, baking powder, baking soda, and kosher salt. Use a pastry cutter or the backs of two forks to cut in the cream cheese and ¼ cup of cold butter until incorporated in pea-sized clumps. Toss in the sprinkles. In a liquid measuring cup, combine the buttermilk and clear vanilla extract. Pour the liquid into the dry ingredients and stir until a shaggy dough comes together. 
3. Dump the dough out onto a lightly floured counter and quickly bring the dough together used floured hands. Gently pat the dough out into a flat rectangle and fold the dough in thirds as you would a letter. Repeat this process twice more and then gently flatten the dough out into a ¾” rectangle. Use a floured 2” biscuit cutter to cut out rounds of dough. Keep the cutter flooured and press straight down. Space the biscuits out on the prepared pan about ½” apart. Pop the pan in the freezer for 5-10 minutes if the dough got warm. Brush the biscuit tops with the melted butter and sprinkle with the remaining 2 teaspoons of sugar if desired. Put the pan in the oven and immediately decrease the heat to 400. Bake for about 15 minutes or until the biscuit tops are beginning to turn golden. 

To prepare the icing:

1. Combine the sugar, butter, and milk, whisking until smooth. Spoon small dollops on top and sprinkle with extra sprinkles if desired. Serve warm.