Yield: 14 SERVINGS
Prep time: 45 MIN
Cook time: 20 MIN
Total time: 2 HR
These cupcakes are moist, flavorful with the perfect amount of lemon, filled with tiny, crunchy poppy seeds. The sweet blackberry buttercream is delicious and beautiful with its deep purple color.
FOR THE LEMON POPPY SEED CUPCAKES CAKE:
1½ cups all-purpose flour
1 teaspoon baking powder
½ teaspoon baking soda
¼ teaspoon salt
½ cup unsalted butter softened to room temperature
1 cup white sugar
3 tablespoons lemon juice, freshly squeezed (about 1-2 medium-sized lemons)
2 tablespoons lemon zest
2 large eggs
1 teaspoon vanilla extract room temperature
⅔ cup sour cream room temperature
1½ tablespoons poppy seeds
FOR THE BLACKBERRY FROSTING:
1½ cups blackberries fresh or frozen
1 cup unsalted butter softened to room temperature
4 cups powdered sugar
¼ teaspoon salt
1 tablespoon cream, if needed
TO MAKE THE LEMON POPPY SEED CUPCAKES:
Preheat the oven to 350°F(177°C) and line 2 muffin pans with liners. You’ll end up with about 14 cupcakes in total.
In a large bowl sift together the flour, baking powder, baking soda and salt. Give them a whisk.
In a separate large bowl, beat the butter, sugar and lemon zest until fluffy.
Beat in the eggs and vanilla extract.
With the mixer on low speed, beat in about ½ of the sour cream followed by about ½ of the flour mixture. Turn off the mixer and scrape down the sides of the bowl.
Repeat the process with the rest of the sour cream and flour mixture.
Gently fold in the lemon juice and poppy seeds.
Spoon the batter into the prepared muffin pans filling each about ⅔ full. You should get about 14 cupcakes.
Bake 1 tray at a time on the middle rack of the oven for 16-20 minutes, or until the tops look set and the inserted toothpick comes out clean. Cool in the pan for at least 10 minutes, then continue cooling on a wire rack.
TO MAKE BLACKBERRY PUREE:
Add the blackberries to a food processor or blender and pulse until smooth.
Push the puree through a metal sieve to remove the seeds, push it through the sieve using the back of a spoon. Do about half the amount at a time.
Transfer the puree (without seeds) to a small saucepan over low heat. Bring to a gentle simmer while stirring occasionally for 10-20 minutes, or until it’s thick like jam consistency. You should end up with about 2-4 tablespoons in volume.
Let cool completely before adding to the frosting.
TO MAKE BLACKBERRY FROSTING:
In a large bowl, beat the butter until soft.
Turn the mixer down to low speed and beat in 2 cups powdered sugar and the salt.
Beat in 2 tablespoons of the thick, cooled puree.
Beat in the rest of the powdered sugar about ½ cup at a time, adding in a little more blackberry puree or cream as needed.
Transfer the frosting to a piping bag (I used a 1M tip) and frost the cupcakes or frost with a knife.
Storage and Make-Ahead Tips: Making these cupcakes the day you plan to eat them is highly recommend. Store in an airtight container at room temperature for up to 6 hours, or in the fridge for up to 3 days. If you’d like to make the cupcakes the day before, make the cupcakes and store them in an airtight container at room temperature. Then make the puree, cool it fully and store in an airtight container in the fridge. Then make the frosting the day you plan to serve the cupcakes.