For the Cupcakes
- 1 and ¼ cup cake flour*
- 1 teaspoon baking powder
- ¼ teaspoon baking soda
- ¼ teaspoon salt, to taste
- ½ cup unsalted butter, room temperature
- ¾ cup granulsated sugar
- 2 egg whites
- 2 teaspoons vanilla
- ¼ cup plain yogurt, room temperature
- ½ cup milk. room temperature (2% or whole preferred)
For the Strawberry Buttercream
- 1 and ½ cups fresh strawberries
- 2 tablespoons granulated sugar
- ¾ cup unsalted butter, slightly softened
- 2½ to 3½ cups icing sugar
- ½ teaspoon vanilla
- 1 tablespoon whipping cream (depending on consistency)
- Preheat the oven to 350F degrees and line a 12-cavity muffin pin with cupcake papers. I got 14 cupcakes total, so I did mine in 2 batches since I only have 1 muffin tin — but you can line 2 trays if you have them.
- In a medium sized bowl, whisk together the cake flour, baking powder, baking soda and salt. Set aside.
- Using a hand held or stand mixer, cream together the butter and sugar on medium speed until light and fluffy (about 2-3 minutes), then continue beating and add in the egg whites and vanilla (about another 30 seconds). Turn off the mixer, scrape down the sides of the bowl and stir in the yogurt. Carefully add in the flour mixture, mixing on low speed followed by the milk. Scrape down the sides of the bowl as necessary, and continue mixing until combined.
- Spoon the batter evenly into the lined muffin cavities — filling each about two thirds of the way full. I ended up with 14 cupcakes total. Bake for 15-18 minutes until an inserted toothpick comes out clean. Mine took exactly 16 minutes. Leave to cool in the pan for about 10 minutes then remove the cupcakes and continue cooling on a wire rack.
- While the cupcakes are cooling, you can start making the frosting. Process the strawberries in a blender or food processor until no lumps remain, then transfer to a small saucepan over medium heat and begin to reduce. Add the granulated sugar, and allow the mixture to come to a gentle boil while stirring occasionally. After the sauce has boiled for about 10 minutes and reduced to about half the volume, remove from the heat and allow to cool fully. It should be thick — almost the consistency of jam. You can speed up this process of cooling the strawberry sauce by putting the sauce in the freezer. If you'd like to remove the seeds, put the sauce through a sieve.
- In a large bowl using a hand held or stand mixer, beat the butter on medium speed until fluffy. Slowly add about 2 cups of the icing sugar and continue beating until combined. Add about 3-4 tablespoons of the cooled strawberry sauce to the batter and continue beating. Make sure your strawberry sauce is room temperature or colder before adding it to the buttercream. Add in the rest of the vanilla and icing sugar about ½ cup at a time until the desired sweetness & thickness is reached. If the icing seems thick, add in a tablespoon of whipping cream and continue beating
- Frost the cupcakes using a piping bag or by spreading the icing with an icing spatula.
*If you don't have cake flour on hand, measure 1 and ¼ cups all purpose flour into a medium sized bowl then remove 2 and ½ tablespoons of the flour. Replace the 2 and ½ tablespoons all-purpose flour by adding 2 and ½ tablespoons cornstarch. Whisk the mixture for about 1 minute then sift.