Lemon Blackberry Cupcakes

Blackberries are one of my favorite fruits.  They are juicier than raspberries, and seem more elegant, perhaps because of their sleek purple-black color.  So, I was really excited to discover that blackberries were this month's ingredient for the Get Your Chef On challenge hosted by White Lights on Wednesday and Four Marrs and One Venus.

I knew I wanted to make a delicious blackberry dessert.  At first I was thinking about blackberry galettes, but I just made galettes recently, and I realized it had been TOO LONG since I'd made cupcakes.  Initially I was planning to make chocolate blackberry cupcakes, but I was over at my mom's, and she really wanted vanilla.  Since she was nice enough to let me heat up her kitchen on a hot day, I had to agree.  Since the blackberries I've been getting are so sweet and juicy, I decided lemons would be a nice counterpoint.

This cake is adapted from a lemon bundt cake recipe in Cook's Illustrated The Science of Good Cooking, which is an awesome book with recipes that were rigorously tested to make the most of the scientific principles at work in the kitchen.  The blackberry frosting is my own creation.

There was almost a disaster when I was decorating these cupcakes.  I thought glaze with frosting on top would be delicious (and I was right), but I didn't realize the frosting would try to slide right off the glaze.  Disaster was averted when I cut little cone-shaped holes into the top of the cupcakes to hold all the buttery frosting.  Phew, that was a close one.

These cupcakes take a little bit of time, but you should make them because they are so summery and so delicious--creamy, buttery, fruity, and tart at the same time.  If you buy a lot of blackberries, which you should, hang on to some--I have another delicious, but much healthier, blackberry recipe coming up soon. 

Ingredients (makes 12 cupcakes; cake and glaze adapted from Cook's Illustrated The Science of Good Cooking):

For the cake:

1 lemon
1 1/2 cups flour
1/2 teaspoon baking powder
1/4 teaspoon baking soda
1/2 teaspoon salt
Scant 1/2 cup buttermilk
1/2 teaspoon vanilla
2 eggs, at room temperature
9 tablespoons unsalted butter, softened but still cool (60 degrees)
1 cup sugar

For the glaze:

1 tablespoon lemon juice
1 tablespoon buttermilk
1 cup powdered sugar, sifted
1/2 teaspoon vanilla

For the frosting:

1 heaping cup fresh blackberries, plus 12 blackberries for decorating
1/4 cup water
2 tablespoons granulated sugar
1 teaspoon vanilla, divided
1 teaspoon lemon zest
12 tablespoons unsalted butter, softened
1/4 teaspoon salt
2 cups powdered sugar, sifted

To make the cake, preheat the oven to 350 and grease and flour a 12-cup muffin tin (or use papers--I didn't because I knew the glaze was going to drip down the sides).

Zest the lemon and squeeze one tablespoon plus 1 teaspoon of juice (save the rest of the lemon for the glaze).  Put half the zest in a small bowl with the juice, reserving the rest of the zest for the frosting.

In a medium bowl, whisk together the flour, salt, baking soda, and baking powder.  In another medium bowl, whisk together the buttermilk, vanilla, and lemon mixture.

In the bowl of a stand mixer fitted with the paddle attachment, cream the butter and sugar on high speed until very fluffy and light (take a full 3 minutes to do this).  Scrape down the sides of the bowl.  With the mixer on low, add the eggs one at a time, mixing to fully combine between the additions.

With the mixer still on low, add the flour mixture in 3 additions, alternating with 2 additions of the buttermilk mixture and scraping down the bowl as needed.  Give the batter one more stir by hand to make sure it's mixed.

Divide the batter evenly among the muffin cups, being careful not to fill them over 3/4 of the way full--without cupcake papers, it's hard to remove a cupcakes that's baked over the edges of the cup.

Bake for 12-18 minutes, or until the cupcakes are light golden around the edges and a toothpick comes out clean.  Cool for five minutes in the pan, then turn out onto a rack, using a small sharp knife to loosen the cakes if necessary.

While the cupcakes are baking, make the glaze.  Combine all the ingredients and whisk until smooth.

While the cupcakes are still warm, pierce the top once or twice with a fork and pour the glaze over.

To make the frosting, heat the blackberries, water, granulated sugar, half a teaspoon of vanilla, and the remaining lemon zest in a saucepan over medium heat.  Simmer, using a spoon to help break up the blackberries, until the berries are turned to mush and the liquid around them is syrupy, 15-20 minutes.  Strain through a fine-mesh strainer, using the back of the spoon to squeeze out as much liquid as possible.  Discard the seedy pulp and set the blackberry syrup aside to cool.

In the bowl of a stand mixer fitted with a paddle attachment, cream the butter until smooth.  Add the blackberry syrup, powdered sugar, salt, and the remaining half teaspoon of vanilla.  Mix until smooth.  If the frosting seems too liquid, put it in the refrigerator for half an hour or so to set up.

When the cupcakes are completely cool, use a paring knife to cut a small cone-shaped piece of cake out of the top of each one (see a picture in this post).  You're doing this because you don't want the frosting to just slide right off the glaze!  Use a spoon or a frosting bag to fill the cavity with frosting, letting it spill over a little.  Place a blackberry, stem end down, in the cavity with the frosting.  Enjoy!

I kept these cupcakes in the refrigerator because it's been so hot and I didn't want the frosting to melt.  They still tasted great on the third day, and there were none left after that.  They will also keep up to 3 days in an airtight container at room temperature.  The cakes texture becomes denser over time (like a pound cake), but it's still delicious.

You might also like:

Salted Caramel Cupcakes

Triple Berry Almond Clafoutis

Lemon Coconut Cupcakes