Preheat the oven to 350°F and line a few cookie sheets with silicone baking mats or parchment paper.
1 1/4 cup packed brown sugar (light or dark), 1/2 cup softened, unsalted butter, 2 Tbsp. cinnamon
Make the cinnamon sugar filling. In a small bowl, combine the brown sugar, softened butter, cinnamon, and salt together until smooth. Set aside.
In a large bowl, combine the dry ingredients: flour, cake flour, corn starch, baking soda, baking powder, salt, and ground cinnamon. Set aside.
2 1/2 cups all-purpose flour, 1 1/2 cups cake Flour, 2 tsp. corn starch , 1 tsp. baking soda, 1 tsp. baking powder, 1 tsp. salt
Place the cubed butter into the bowl of a stand mixture and secure the paddle attachment. Turn the mixer on medium speed and cream for about 1 minute. Then add in the granulated sugar and cream until smooth, about 1-2 minutes. It should like almost like a paste. Scrape down the sides of the bowl as needed.
1 cup cold, unsalted butter, cubed (16 Tbsp.), 1 1/4 cup granulated sugar
Add in the eggs, egg yolks and vanilla extract and blend until mixed. Scrape down the sides of the bowl again.
2 large eggs, 2 large egg yolks , 1 tsp. vanilla extract
Gradually add in the dry ingredients, about 1/4 cup at a time. Being careful not to over mix.
On a clean, lightly floured surface, press the cookie dough into a long rectangle. (For sizing, you can use a 9x13 inch dish for reference.) Flatten out using your hands, no rolling pin necessary.
Spoon the cinnamon sugar filling onto the dough and into an even layer.
Roll the dough up, starting on the long edge, being careful not to tear the dough. (If you floured your work surface this shouldn't be an issue but if it does tear a little, it's out the cookie dough is forgiving and you'll be rolling into balls anyways).
Cut the cookie dough into equal slices. You should be able to get about 20-24 cookies.
Roll cookies into balls, being sure to seal the filling inside so it doesn't ooze out. I like to pinch the bottom so it's sealed, and then leave some of the swirl on top. Place on prepared cookie sheet and press down slightly to flatten cookie a little. Bake for 8-11 minutes or until edges are lightly golden brown. I always underbake just a little for the perfectly soft, tender cookies.
If desired, use a round cookie cutter or the back of a spoon to gently “cookie scoot” around the edges right after baking to create perfectly round cookies, especially if some of the filling oozed out or escaped. Cool cookies on baking sheet for ~10-15 minutes then transfer to cooling rack. Make the cream cheese frosting. In a medium sized bowl, mix together the softened cream cheese and butter using a hand mixer. Then add in the powdered sugar, vanilla and salt. Mix until smooth. Add more powdered sugar or a splash of heavy cream, as desired for perfect consistency.
8 oz. full-fat cream cheese, softened , 1/2 cup unsalted butter, softened, 2 1/2 cups confectioners sugar, 1 tsp. vanilla extract, 1/2 tsp. salt
Spread or pipe frosting on top of cooled cookies, sprinkle with cinnamon if desired. Store cookies in the fridge for up to 5 days if you frosted them, or unfrosted cookies in an air-tight container at room temperature for up to a week.