Step 1

Preheat oven to 350°F. Grease and line an 8 x 8″ baking pan with parchment paper and set aside.

Step 2

In a standing mixer with a paddle attachment, cream the melted butter and sugar on high speed for 30 seconds. Add in the egg and bourbon and mix for another 30 seconds.

Step 3

In a separate bowl, combine flour, cream of tartar, and salt. Fold dry ingredients into wet, mixing until combined. Place into prepared baking pan.

Step 4

Mix together additional sugar and cinnamon and sprinkle over bars. Bake for 30-35 minutes, until a knife in the center comes out mostly clean, then allow to cool completely before cutting into squares!