Blackberry Lemon Cupcakes
In theory, cupcakes are the world’s most lovable dessert; a tiny cake for one, all frosted up and wearing its own little jacket. In practice, they’re often unpleasant, tooth-achingly sweet, and texturally disappointing.
Not this one. Springy and sophisticated, this lemony cupcake is frosted with a featherweight buttercream that delivers a bright burst of juicy tartness from the fresh blackberries. The lemon really shines through, thanks to the generous amount of zest rubbed into the sugar. If you have a nostalgic relationship to cake-box cake, the crumb will not let you down — it’s moist and dense in the best way. We think it’s the ideal dessert for a birthday, a shower, even an intimate backyard wedding. The rosy frosting against the lemon cake is so pretty that these cupcakes really deserve to be served on a table next to fresh flowers.
Some notes from the test kitchen bakers: To get the most consistent crumb with no air bubbles, follow the mixing times and incorporate the ingredients well. Let the eggs come to room temperature (trust us) before adding the butter. If the buttercream is too hot or cold, it will break. If this happens, do not panic. Just bring the frosting to room temperature and whip it again — it will come back together.
Our tips: The buttercream can be made in advance; keep it covered in the refrigerator then bring it to room temperature before whipping. Feel free to sub in another berry (raspberries would be delightful here) to mix up the flavors.
For the cupcakes:
1 ¾ cups cake flour
1 ¼ tsp baking powder
½ tsp baking soda
¼ tsp kosher salt
½ cup whole milk, room temperature
½ cup sour cream, room temperature
1 ½ tsp vanilla extract
1 cup granulated sugar
Zest from 1 lemon
1 stick unsalted butter, room temperature
2 egg whites, room temperature
For the buttercream:
12 oz blackberries, 12 berries reserved for garnish
1 ½ Tbsp lemon juice
1 cup plus 1 Tbsp granulated sugar, divided
4 large Gelson’s eggs
1 tsp vanilla extract
1 lb unsalted butter, softened, cut into 2” pieces
Preheat the oven to 350°. Line a 12-cup muffin tin with paper liners.
To make the cupcakes: Sift the cake flour, baking powder, baking soda, and kosher salt into a medium mixing bowl. Set aside.
In a liquid measuring cup, whisk together the whole milk, sour cream, and vanilla extract. Set aside.
In the bowl of a stand mixer, combine the granulated sugar and lemon zest. Rub the mixture between your fingers until the sugar is fragrant and light yellow in color.
Add the unsalted butter. Using the stand mixer with the paddle attachment, mix on medium speed, scraping down the sides of the bowl as needed, until light and fluffy, 2 to 3 minutes.
Reduce the speed to low, slowly pour in the egg whites, and mix until absorbed, about 1 minute.
Add one-third of the dry ingredients and mix until just combined, then add half of the milk mixture and mix until just combined. Repeat, alternating between the dry and wet ingredients, until all of the ingredients are used. Continue to mix for 30 seconds, until the batter is smooth.
Transfer the batter to the muffin pan, filling the wells two-thirds of the way full. Tap the pan on the counter to release any air bubbles. Bake for 20 to 22 minutes, or until lightly golden and an inserted toothpick comes out clean. Let cool completely.
To make the blackberry buttercream: Combine the blackberries, lemon juice, and 1 Tbsp granulated sugar in a small saucepan. Mash the blackberries with a potato masher, bring to a simmer, and cook until the liquid is reduced to ¼ cup, 7 to 8 minutes. Strain the juice through a sieve and let cool to room temperature. Discard the blackberry pulp.
In a small pot, bring 2” of water to a gentle simmer.
In the bowl of a stand mixer, combine the remaining 1 cup granulated sugar, eggs, and a pinch of kosher salt. Place the bowl over the simmering water, whisking occasionally, until the mixture reaches 160° on an instant-read thermometer. Then add the vanilla extract.
Using the stand mixer with the whisk attachment, beat the mixture on medium-high speed until light and fluffy and room temperature, 7 to 10 minutes.
Reduce the speed to low and add the unsalted butter, one piece at a time, until combined. Once all of the butter is incorporated, add the blackberry syrup and mix until combined. Increase the speed to medium-high and whip until fluffy, about 1 minute.
Spoon or pipe the buttercream onto the cupcakes and top each one with 1 fresh blackberry. Serve immediately or store in the refrigerator for up to 3 days. Bring to room temperature before serving.