Preheat the oven to 365F and line a cookie sheet with parchment paper.
In a medium bowl whisk the butter and egg until creamy, add the flours, stevia, baking soda, vanilla extract, and salt, continue whisking until all the ingredients are well combined.
Refrigerate dough for 10 minutes.
With a small cookie scoop, drop the dough at least two inches apart onto cookie sheet.
Bake for 10- 12 minutes or until light golden brown, the center should be soft.
Let them cool for at least 5 minutes before removing from the cookie sheet.
Serving Size 1 cookie
* Percent Daily Values are based on a 2,000 calorie diet. Your daily value may be higher or lower depending on your calorie needs.