Preheat the oven to 350 degrees F.
In the bowl of a stand mixer, beat the butter until creamy. Add the brown sugar and beat 1-2 minutes until well mixed and no chunks of brown sugar remain.
Add the egg, egg yolk, vanilla extract and maple syrup. Beat two minutes, scraping down the sides of the bowl as needed, until mixture lightens in color and looks very fluffy.
In another bowl, combine the baking soda, salt, cinnamon and flour. Add the flour mixture to the wet ingredients and mix just until the dough comes together and looks well combined.
Line a baking sheet with parchment paper. Use a medium cookie dough scoop to portion out 2 tablespoons of dough, 8-10 dough balls per cookie sheet.
Bake the cookies 10-12 minutes, just until the edges are set. Tops will be puffed and a little cracked, but will still be very soft. Remove cookie sheet from oven, but allow the cookies to cool on the sheet for 10 minutes before removing to a cooling rack. Cool completely before glazing.