Preheat oven to 375.
Cream butter and sugar with an electric mixer until smooth.
Add egg and vanilla, mixing well until combine, about 2 minutes.
Stir in flour, baking powder, salt, and 1 ½ teaspoons cinnamon. Mix until dough comes together. Add in milk. If dough is still crumbly, add milk 1 tablespoon at a time until it comes together. Refrigerate for 30 minutes.
In a bowl combine remaining sugar and cinnamon. Remove dough from fridge and roll into big 1 ½ inch balls. Roll in cinnamon sugar mixture and place on baking sheet. Lightly press down on dough to flatten it. Bake at 375 for 10-12 minutes.
