Place the butter and sugar in the bowl of an electric mixer and beat on medium until pale and fluffy, about 3 minutes.
Reduce speed to low and beat in the egg and vanilla.
In a small bowl, whisk together the flour, baking powder and salt. Add the flour mixture to the mixer and beat on low until just combined.
Chill the dough while the oven is preheating to 375 degrees.
When oven is ready, form the dough into 1 T size balls.
Whisk the 1/2 C sugar and 1 T ground cinnamon together in a bowl.
Roll each dough ball in the sugar and cinnamon until well coated. Place the dough balls on parchment lined baking sheets, leaving 1-2 inches in between.
Bake for 10 minutes.