blackberry lime cake

I've had this cake on my list for most of the summer. And sweet lord, it is good. It also has like a whole lot more steps than I normally take on. But, the minute I tasted this frosting I knew it was all worth it. I have literally never tasted anything so light and airy in my life. Pure heaven.

Candidly, I made this cake for a casual family gathering. My birthday. I know it's not something normally accepted for a birthday girl to make her own cake - but it is what I wanted. And what the birthday girl wants, the birthday girl gets. So my parents don't get shamed for this, here is text message evidence of the initial decline when I asked to make the cake.

Here are a few things to know about this cake:

• Blackberry Compote // you can use frozen berries. My grocery store didn't have fresh blackberries in-stock and we all lived after eating this cake. No big deal.
• Lime Cake // the current flavor profile is subtle. My aunt didn't even take note of the lime flavoring. If you want more of a boost, add in maybe the zest of two limes instead of one.
• Cake layers // The original recipe called for 3 eight inch round layers. I'm still really loving my 7 inch round pans. This resulted in a 4-layer cake versus 3-layers. Not that big of a deal. When the batter is completed mixed you end up with 6 cups before dividing it between the pans.
• Weird layers // I'm not totally sure what happened but my first two layers that I cooked didn't have a great formation on the edges of the pan. For the last two, I had run out of parchment paper (doh!) and ended up just spraying and flouring the pan. They came out the best. But if you aren't using a spring form pan, you absolutely should have parchment paper. No questions.

Make the Blackberry Lime Cake:

1. Preheat oven to 350F. Butter and lightly flour your round pans. Line with parchment paper circles.
2. In a small bowl, combine milk and lime juice. Stir to combine and set aside for milk to curdle. 
3. In the bowl of a stand mixer, beat butter and sugar on medium-high using the paddle attachment. Beat until pale and fluffy, about 3 minutes.
4. With the mixer on low, add eggs one at a time. Mix well after each egg.
5. Add vanilla extract and mix to combine.
6. In a separate bowl, whisk together flour, baking powder, baking soda and lime zest. 
7. Add the flour mixture in three batches, alternating with the milk, beginning and ending with the flour mixture. Do not over mix. Stop the mixer and scrape down the bowl and the mixer blade.
8. Divide batter evenly between the round pans.
9. Bake for 25-27 minutes, or until toothpick inserted into center comes out clean.
10. Let cool in pans for 5 to 10 minutes, then remove to wire rack to finish cooling.

Make the Blackberry Reduction:

1. Combine blackberries, sugar and lime juice in a pan over medium heat.
2. Cook 10 to 15 minutes until the juices are bubbly and the berries are soft enough to smash with the back of a spoon.
3. Press the mixture through a fine mesh strainer into a clean bowl to remove the seeds. Use the back of your wooden spoon to really press as much pulp through as you can. Scrape the underside of the strainer to get all of the accumulated blackberry pulp. Discard seeds and return strained puree back to the pan.
4. Cook on medium, stirring with a wooden spoon, until reduced to only a few tablespoons, about 10 minutes.
5. Pour into a small bowl and cover with plastic wrap. Allow to cool.

Make the Blackberry Buttercream:

1. Place egg whites and sugar into the bowl of a stand mixer, whisk until combined.
2. Place bowl over a pan of simmering water to create a double-boiler. Whisking constantly, heat the egg mixture until it registers 160 degrees on a candy thermometer. Carefully transfer the bowl onto the stand mixer.
3. Using the whisk attachment, beat the egg white mixture on high speed for 8 to 10 minutes until the bowl is no longer warm to the touch and the meringue is fluffy, glossy and holds a stiff peak.
4. Switch to the paddle attachment. With the mixer on low, slowly add cubed butter and mix until incorporated.
5. Whip on medium-high until silky and smooth, about 3 to 5 minutes.
6. Add blackberry reduction and whip again until incorporated. The buttercream may look like it’s broken at some point. Keep mixing until it is completely smooth.

Assemble the Cake:

1. Place one layer of cake onto serving plate or cake stand and top with about one cup of blackberry frosting.
2. Repeat with second cake layer, more frosting and then last layer of cake. Crumb coat and frost cake with remaining frosting.

Shopping List

Blackberry Lime Cake:3 cups all-purpose flour
1 tablespoon baking powder
½ teaspoon baking soda
2 tablespoons lime zest
¾ cup whole milk
¼ cup lime juice
8 ounces butter, room temperature
2 cups granulated sugar
4 eggs, room temperature
2 teaspoons vanilla extract

Blackberry Reduction:12 ounces blackberries (fresh or frozen)
1 tablespoon granulated sugar
1 tablespoon lime juice

Blackberry Buttercream:6 egg whites
1 ½ cups granulated sugar
1 ½ cups butter, softened
3 tablespoons blackberry reduction