In the bowl of a stand mixer fitted with the paddle attachment, beat together the Brown Sugar (1 1/2 cup), Powdered Confectioners Sugar (1/2 cup), and Unsalted Butter (1 cup) at medium speed until smooth and fluffy.
Add the Egg (2), Whole Milk (2 tablespoon), and Vanilla Extract (1 tablespoon) and continue mixing until combined.
In a medium bowl, whisk together the All-Purpose Flour (4 cup), Sea Salt (1 1/2 teaspoon), and Baking Soda (1/2 teaspoon) to combine.
Empty the flour mixture into the butter mixture and reduce the speed to low, mixing until they are just combined.
Remove half of the dough from the mixer and add the Ground Cinnamon (2 teaspoon) to the remaining dough. Mix together until well combined.
Form each dough into a ball and then pat them out into a rough rectangle, cover it, and refrigerate it for 1 hour.
Preheat the oven to 400 degrees F (205 degrees C).
Roll each dough out into a 9x12-inch rectangle.
Place the cinnamon dough on top of the plain dough and roll out further into a 10x14 inch rectangle.
Roll the dough together from long end to short end. Roll the dough back and forth to adhere.
Cut out the cookies into 48 cookies.
Set the cookies 2 inches apart on a baking sheet and bake for about 10 minutes, before they turn golden.
In a standing mixer, cream the Cream Cheese (4 ounce) and Butter (1/4 cup) together until smooth. Add the Powdered Confectioners Sugar (2 cup) and Vanilla Extract (1 teaspoon) and beat until a smooth frosting appears. Place into a large zip lock bag and cut the corner off one of the edges.
Squeeze about a tablespoon onto the bottom of one cookie, then sandwich the other cookie on top. Repeat with the remaining cookies.