Handful of frozen blueberries
1/2 cup banilla or vanilla yogurt
1 cup milk
Put all ingredients in a blender and process until smooth.
* freeze fresh ones when they get too ripe
For cakes Whisk together flour, cocoa, baking soda and salt in a bowl until combined.
Stir together milk and vanilla in a small bowl.
Beat together butter, apple sauce and brown sugar in a large bowl with an electric mixer at medium-high speed until pale and fluffy.
Add egg, beating until combined.
Reduce speed to low and alternately mix in flour mixture and milk in batches and mixing until smooth.
Spoon 1/4-cup mounds of batter about 2 inches apart onto 2 parchment lined baking sheets.
Bake until tops are puffed and cakes spring back when touched, about 11 to 13 minutes.
Transfer with a metal spatula to a rack to cool completely.
Beat together butter, confectioners sugar, marshmallow and vanilla with electric mixer at medium speed until smooth, about 3 minutes.
Spread a rounded tablespoon filling on flat sides of half of cakes and top with remaining cakes.