Preheat oven to 350°. Combine topping mix and 6 Tbsp. melted butter. Stir in ¼ cup sour cream; set aside. Combine cake mix, 2 Tbsp. melted butter and ¾ cup sour cream until sticky dough forms. Stir in ¾ of the prepared topping into batter; gently stir in blueberries. Scoop dough into paper-lined or greased muffin cups. Spread remaining topping over dough. Bake 25 minutes or until toothpick inserted in center comes out clean. Makes 12 muffins.
Always check the labels of ingredients in recipes to confirm they are gluten-free, and ensure your space is free from other possible sources of gluten. Since ingredient formulas can change and vary among other brands, Tastefully Simple cannot ensure that prepared recipes will be gluten-free.