Pre-heat oven to 425. Line a rimmed baking sheet with parchment paper and set aside.

In a large bowl, stir together the dry ingredients (flour, sugar, salt and spices). Using a fork, cut butter into the flour until mixture resembles course crumbs with some pea-size butter pieces remaining.  Add buttermilk, stirring until combined.

Turn dough out onto a well-floured surface. Knead dough several times until it comes together. Pat into a 10x9 rectangle. Using a 2 1/2 inch round cutter dipped in flour, cut dough without twisting cutter. Reroll scraps as needed. Place rounds on prepared pan, spacing 2 inches apart. Brush tops with melted butter and sprinkle with cinnamon sugar, (reserving leftover butter for another brushing after baked). Freeze until chilled, about 15 minutes.

Bake until golden brown, about 11-12 minutes. While the biscuits are still warm, brush the remaining melted butter.

In a small bowl, whisk together all ingredients until smooth and whipped. Spread onto warm biscuits and serve.