Preheat oven to 350 °F
Line a baking sheet with parchment or a silpat liner, set aside
In medium sized mixing bowl combine flour, baking powder, and salt. Set aside.
In the bowl of an electric mixer combine butter and sugar and mix until creamy. Add in egg and mix.
Add the flour in, about ½ at a time, until fully combined.
If dough is too warm, chill for 10 minutes in refrigerator.
Roll dough into 1 ½ inch balls and roll in the cinnamon sugar mixture.
Place coated balls on baking sheet about 2 inches apart (they will spread when cooking).
Flatten cookies with the bottom of a glass.
Bake for 7-10 minutes until just golden brown.
Remove from oven and let sit on pan for 5 minutes, then move to a cooling rack.