Preheat oven to 350°.
While the oven is preheating make the cookie dough. Cream together the butter and sugar until light and fluffy.
Scrape the sides, add in the eggs, and vanilla extract. Beat until mixed.
Scrape the sides and add in the flour, baking powder and cinnamon. Mix until thoroughly combined.
Scoop out 1/3 cup of dough and roll into a ball. Repeat with remaining dough.
Combine the sugar and cinnamon in a bowl, toss and press the cinnamon and sugar onto the cookie dough. Flatten the cookie dough by gently so it is in the shape of a hockey puck. Repeat with remaining dough.
The cookies will spread so make sure to leave room. I tend to only put 6 cookies per pan.
Bake at 350° for 12-15 minutes or until the centers of the cookies have puffed up and are no longer glossy.
While the cookies are cooling on the pan, make the frosting, by whipping the butter, cream cheese, vanilla and 1/4 cup dulce de leche until smooth.
Add the powdered sugar, one cup at a time, letting the ingredients combine completely before adding the next cup.
Add milk a tsp at a time until you've reached your desired consistency, if needed.
Add the frosting to a piping bag fit with a large closed star tip (2D). Set aside.
Once the cookies have cooled on the pan for about 15 minutes, spoon about a tbsp of dulce de leche onto the top of the cookies.Pipe a dollop of frosting into the center of each cookie. Serve warm.