The surprise in these strawberry cupcakes? More strawberries! Pureed strawberries are in the batter, alongside cake flour, butter, sugar, milk, baking powder and eggs. The frosting is a strawberry buttercream that is placed inside of the baked cupcakes to form the “surprise” filling. Once you have filled them, replace the top part of the cupcakes, frost normally, and add on a slice of fresh strawberry. The stunning results are the ideal summertime treat.