Whisk together flour, Isopure® Whey Protein Isolate Unflavored, baking powder and salt in a medium bowl and set aside.

In the bowl of a standing mixer, fitted with a paddle attachment, combine butter and sugar and mix on medium speed 1 - 2 minutes until well combined.

Reduce to medium low and add egg and vanilla.

Mix util combined, about 40 seconds.

Reduce speed and gradually add the flour mixture, scraping down the sides of the bowl as needed.

And beating just until dry ingredients are combined.

Wrap dough in plastic wrap in 2 - 3 parts and chill for 1 or more hours.

If you are rolling dough between parchment paper sheets you can roll out immediately.

Roll dough on floured surface (if not using parchment) to 1/8 inch thick or slightly thicker.

Preheat oven to 350.

Cut out desired shapes and bake for 9 - 12 minutes until golden on edged and middle is firm to touch.