In a mixing bowl, cream together butter and sugar until light and fluffy.
Add egg and vanilla extract and mix until just combined.
In a separate bowl, whisk together flour, cinnamon powder, baking powder.
Dump this dry mixture into the wet mixture and mix until just combined. Use your hands, if necessary, to mix everything together into a cookie dough consistency.
Cover and chill in the fridge for about 1 hour so that it's easier to handle and don't spread while baking.
Scoop out small portions of the dough and roll them into balls.
In a small bowl, mix together sugar and cinnamon.
Roll cookie dough balls in cinnamon sugar until fully coated.
Place them on a cookie tray, lined with parchment paper.
Bake at 350 degrees for 10-12 minutes or until cookies are golden brown and edges are firm.
Let the cookies cool down and enjoy!