01 - Whisk together flour, baking powder, salt, and cinnamon in a medium bowl. Set aside.
02 - Using an electric mixer, beat butter and granulated sugar in a large bowl until light and fluffy, approximately 2 to 3 minutes.
03 - Add egg and vanilla extract to the butter mixture and mix until fully incorporated.
04 - Gradually add the dry ingredients to the wet mixture, mixing on low speed until just combined.
05 - Divide the dough into two equal portions, shape each into a disk, wrap in plastic wrap, and refrigerate for at least 30 minutes.
06 - Preheat oven to 350°F. Line baking sheets with parchment paper.
07 - Combine sugar and cinnamon for coating in a small bowl.
08 - Roll chilled dough into 1-inch diameter balls, then roll each ball in cinnamon sugar. Arrange the balls on prepared baking sheets, spacing them 2 inches apart.
09 - Gently flatten each ball using the bottom of a glass to create even thickness.
10 - Bake for 9 to 11 minutes until the edges become lightly golden.
11 - Allow cookies to cool on baking sheets for 5 minutes before transferring to wire racks to cool completely.