In a bowl with an electric mixer cream the butter and sweetener until light and fluffy. Add the sour cream and vanilla and beat until combined. Add the eggs one at a time mixing after each.
Stir in the flours, baking powder, and salt until thoroughly combined. Divide batter between 12 muffin cups lined with paper liners.
Bake at 350 for 20-25 min. Some ovens will take up to 30. You want the cupcakes to be firm to the touch and golden brown.
Nutrition: The nutrition facts are for one of the keto cupcakes. There are 1.9 NET carbs per serving.Storage: I store all my keto baked goods in the fridge but these can be left at room temperature for up to 2 days if you prefer. They last in the refrigerator for 2 weeks or freeze for up to 3 months. They do freeze very well.Make sure to check out the video with this blog post! It features these cupcakes with my Keto Cream Cheese Frosting.Notes on Sweeteners: