Lemon Cupcakes with Blackberry Buttercream
For the cupcakes:
1 3/4 cups all-purpose flour
1 1/2 teaspoons baking powder
1/4 teaspoon salt
1/2 cup sour cream (I used full fat)
1/2 cup milk (I used whole)
2 teaspoons vanilla extract
2 large egg whites, at room temperature
1 stick (4 ounces) unsalted butter, melted
1 cup granulated sugar
Zest of one lemon (about 2 teaspoons)
For the Blackberry Buttercream:
1 cup blackberries
2 tablespoons lemon juice
1 stick (4 ounces) unsalted butter, VERY soft
4 ounces cream cheese, VERY soft
1/2 teaspoon salt
4 cups confectioners sugar (more if needed)
1 tablespoon heavy cream (more if needed)
1) Preheat oven to 350 degrees (F). Line a 12 mold muffin tin with paper liners; set aside.
2) In a medium bowl combine flour, baking powder, and salt; mix well to combine. Set aside.
3) In a large measuring cup or bowl combine sour cream, milk, vanilla, and egg whites; mix well to combine. Set aside.
4) In a small bowl combine sugar and lemon zest. Using your fingertips, rub the zest IN to the sugar, until fragrant and well combined.
5) In a large bowl or stand mixer fitted with the paddle attachment beat melted butter and sugar on medium speed until well combined; about 2 minutes.
6) Slowly add the flour mixture to the butter/sugar combination, beating until just combined. Add in sour cream/milk/egg combo and beat on low until *just combined. Over-mixing will result in a dryer/denser cake.
7) Divide the cupcake batter evenly into the 12 molds, then place the pan in the oven. 8) Bake for about 16 minutes, or until a toothpick inserted into the center of a cupcake comes out clean. Allow cupcakes to cool completely before topping with frosting.
For the blackberry buttercream:
1) Combine the blackberries and lemon juice in a small saucepan.
2) Bring to a simmer over medium heat, and stir constantly until blackberries have become soft enough to mash effortlessly. It will look like blackberry jam.
3) Once the mixture can coat a spoon (you will have about 1/3 cup of blackberry puree) remove from heat.
4) Place a fine-mesh strainer over a small bowl and push the puree though, leaving any seeds/large chunks behind. Allow mixture to cool completely before using.
When ready to make buttercream:
1) Place butter and cream cheese in a large bowl, or in the body of a stand mixer.
2)With a handheld mixer, or with the whisk attachment on your stand mixer, beat butter on medium-high until completely smooth; about 1 minute.
3) Add in the blackberry puree and beat until completely combined.
4) Add in the confectioners sugar, one cup at a time, on low speed.
5) Once all of the sugar has been added, add in the cream, then beat on high-speed for 1-2 minutes, or until light and fluffy. Ice cupcakes as desired.
*Cupcakes can be made up to 6 hours ahead of time, but be sure to store in the fridge and bring to room temperature 30 minutes before serving*