For the cinnamon filling:
8 oz. unsalted butter, diced and softened
1/2 cup brown sugar
1/4 cup ground cinnamon
1 tsp. ground nutmeg
For the cream cheese topping:
1½ cups powdered sugar
8 oz. cream cheese, softened
4 oz. unsalted butter, softened
1 tsp. vanilla extract
1/2 tsp. kosher salt
For the biscuit dough:
2¼ cups all-purpose flour
2¼ cups cake flour
2 Tbs. granulated sugar
2 Tbs. + 2 tsp. baking powder
2½ tsp. kosher salt
1/2 tsp. baking soda
8 oz. unsalted butter, diced and frozen
3 cups buttermilk
For the cinnamon filling:
Using a handheld or stand mixer, beat the ingredients in a bowl until evenly combined. The filling can be made ahead of time and refrigerated but will need to come to room temperature before use.
For the cream cheese topping:
Put the powdered sugar, cream cheese, and butter in the bowl of a stand mixer fitted with the paddle attachment and mix on medium speed until combined with no lumps. Add the vanilla extract and salt and continue mixing until the topping becomes light and fluffy. The topping can be made ahead of time and refrigerated but will need to soften slightly before use.
For the biscuit dough:
Combine all of the ingredients except the butter and buttermilk in a large bowl and mix well. Put the butter and one cup of the flour mixture in a food processor and pulse until the butter is in uniform pea-size pieces. Add them to the bowl of the flour mixture, gently stirring and folding them in with a wooden spoon. Stir in the buttermilk until a dough starts to form. Do not over mix. Flip the dough out onto a floured surface.
Use your fists to push the dough down and flatten it out and a rolling pin to give it a smooth surface. Fold the dough over itself to create a layer and roll it out slightly to seal the fold. Repeat this procedure three more times. Roll the dough into an eight- by 12-inch rectangle. Place on a parchment paper-lined baking sheet and freeze for 15 to 20 minutes.
Meanwhile, preheat the oven to 350°F, and line another baking sheet with parchment.
Spread the cinnamon filling onto the dough and use an offset spatula to evenly distribute it. Roll the dough tightly lengthwise into a log. (Note: The dough won’t be frozen solid. It’s only going into the freezer to keep the butter very cold.) Cut the roll into six 1¼-inch slices and place them onto the prepared baking sheet. Bake the pinwheels for 25 to 30 minutes, rotating the baking sheet halfway through. Let them stand at room temperature for 15 minutes. Spread the cream cheese topping over the rolls and serve.