In a small bowl, stir together the cinnamon and sugar until well combined. Scoop your dough into 2-tablespoonfuls and roll each ball of dough in the cinnamon sugar mixture to coat it fully. Place the rolled dough onto your baking sheet, leaving space for spreading as they bake. Bake for 10-12 minutes, or until the cakes are puffy all over and lightly golden at the edges. You really don't want to over-bake these! Cool the cookies completely before frosting.
In a large bowl, beat together the butter and cream cheese until well combined and fluffy. Then add in the powdered sugar, cinnamon, and salt, and whip until a stiff frosting forms. Fill your COOLED cookies generously with the mixture!