Preheat the oven to 350 degrees.
Line two baking sheets with parchment paper. Set aside.
Cube the butter into 1 cm pieces.
Use a hand mixer or a stand mixer fitted with the paddle attachment to cream the butter and sugar. Cream on high for 1-2 minutes, or until the mixture is smooth (see photo above).
Add in the egg and vanilla extract. Mix until combined.
In a separate bowl, whisk together dry ingredients (flour, corn starch, cinnamon, salt, baking powder, baking soda).
Add the dry ingredients to the wet ingredients in 2-3 portions. Mix until well combined, then scrape down the bowl once complete. Set aside.