Preheat oven to 350. Line a large cookie sheet with parchment paper.
Cream together the butter, cream cheese, and sweetener with an electric mixer. Add in the egg yolk and vanilla and mix.
Add in the rest of the dough ingredients and mix until incorporated.
With a large cookie scoop, scoop dough into 10 balls, and roll in the additional powdered erythritol. Place the balls of dough on the prepared baking sheet. Press down gently until they are half an inch high.
Bake for 10-12 minutes until they are barely golden and no longer look wet on top. Do not over bake or you will lose the gooey butter cookie texture.
Store at room temperature for 2-3 days. For longer storage they can go in the refrigerate but need to be warmed before serving for the right texture.
Notes
Nutrition: the nutrition facts are for 1 cookie when making 10 big cookies. Each cookie has 3 NET carbs.Powdered Erythritol: you use ¼ cup in the cookie batter and then roll the cookies in an additional ¼ cup powdered erythritol. To Reheat: place the cookies on a microwave-safe plate and heat up for 10 seconds or so until they are hot. Don’t overheat them in the microwave, or they will become hard. To Freeze: freeze for up to two months. Keep them in a freezer-safe bag or container—thaw and reheat before eating. Notes on Sweeteners: I have not tried subbing other sweeteners in this recipe so I'm not sure they will work. This particular combination of a granular sweetener and a powdered sweetener makes these the perfect texture.