Preheat oven 400°F.
Line a cookie sheet with parchment paper, set aside.
In a medium mixing bowl, combine softened butter, erythritol, and stevia. Mix together until smooth.
Mix in eggs, sour cream, and extract into butter mixture.
In a separate bowl, combine almond flour, coconut flour, baking powder, and salt. Blend together.
Add dry ingredients to wet ingredients. Combine until well incorporated.
In a food processor pulse frozen cranberries until there are no whole cranberries just chunks. [Note: You can cut up fresh cranberries if you do not have a food processor or you do not want to freeze your cranberries. I just find it easier to cut them up this way.]
Fold in cranberries and walnuts until evenly incorporated.
Drop spoonfuls of cookie dough on the parchment lined cookie sheet.
Leave an inch or two between each cookie.
Bake for 12-14 minutes or until the cookie starts to brown slightly on top.
Let cool completely before removing from cookie sheet.
Store in an airtight container.
Yields: 18 cookies