These cupcakes are more muffin than cake, with only a hint of sweetness. But paired with the tangy sweet strawberry rhubarb filling and the creamy punch of cream cheese frosting, the flavors meld wonderfully together. Note, though fresh berries are always preferred, I suggest using frozen in the batter unless you’ve laid your hands on some supreme fresh ones. You really need the strawberries to be full in flavor and perfectly ripe.
Cupcake recipe adapted from Martha Stewart
For the Cupcakes
2/3 cup strawberries, either fresh or frozen (thawed)
1 1/2 cups unbleached all-purpose flour
1 tsp baking powder
1/4 tsp salt
1/4 cup whole milk
1 tsp vanilla extract
1/2 cup unsalted butter, at room temperature
1 cup sugar
1 large egg
2 large egg whites
For the Strawberry Rhubarb Filling
1 lb fresh strawberries, hulled and chopped
3-4 stalks rhubarb, chopped
1/4-1/2 cup sugar (depending on sweetness of strawberries)
1/2 cup water
1 Tb lemon zest
Pinch of salt
1.5 – 2 Tbs cornstarch
For the Vanilla Bean Cream Cheese Frosting
12 oz (1.5 packages) cream cheese, at room temperature
1/4 cup unsalted butter, at room temperature
1/2 vanilla bean
1 tsp vanilla extract
4-5 cups powdered sugar
1. Preheat oven to 350 degrees and line a muffin pan with paper liners. Purée the strawberries in a blender or food processor – you want to have 1/3 cup of puree for the batter.
2. In a medium bowl, combine the flour, baking powder, salt. In another bowl combine the milk, vanilla extract, and 1/3 cup of strawberry puree.
3. Cream butter on medium-high speed until fluffy, then add sugar. Add the egg and egg whites, combine well. Add half of the flour mixture, then the milk and strawberry mixture, then the remaining flour. Scrape down the sides of the bowl as needed. Divide batter evenly between 12 muffin cups and bake 20-23 minutes until a toothpick inserted in the center comes out clean. Cool completely on a wire rack.
4. To make the strawberry filling, combine all ingredients – except for the cornstarch – in a large saucepan and bring to a boil over medium heat. Reduce and simmer for 1 hour or until rhubarb begins to break down. Remove from the heat and allow to cool slightly then purée the mixture in a food processor, strain, and return to the saucepan. Sprinkle in the cornstarch, whisk to break up any clumps, and cook over low heat until thick. Allow to cool completely.
5. To make the frosting, cream together the butter and cream cheese in the bowl of an electric mixer. Split vanilla bean in half length-wise and scrape the seeds – add to the mixer and beat until seeds are evenly distributed. Add the vanilla extract and powdered sugar. Beat to combine well.
6. To finish, fill a piping bag with strawberry rhubarb filling, insert tip gently into cupcake and fill with about 1 Tb. Frost, decorate, and serve!