Lemon Layer Cake

Photo Courtesy of America's Test Kitchen

One of my closest friends, Cristina, had her 30th birthday last week, so naturally I volunteered to make the cake – what better occasion to make a whole cake and NOT leave it around the house for me to eat on all week!  I was very excited because Cristina requested either a lemon or a coconut cake and I had just so happened to be dying to try making a cake with homemade lemon curd. 

My mom recently ordered “The Complete America’s Test Kitchen Cookbook” after rave reviews from friends at church.  Since I couldn’t find a lemon curd cake recipe in my grandma’s stockpile, I thought, why not try out Mom’s new cookbook.  After some perusing, I chose a recipe for lemon layer cake, which is a white butter cake, lemon curd filling, and a classic 7 minute frosting (with a new improved method that’s practically fool proof). 

Overall, the cake turned out amazing!  It was pretty time consuming and I did have a bit of a mishap with the eggs; subsequently, making two additional trips to the store along with several extra cartons of eggs.  But in the end, it tasted great and it was definitely a crowd pleaser.  I’m also an America’s Test Kitchen convert – the recipes can be long and somewhat involved, but if you just follow the step by step process, chances are it will turn out great!

My cake - I promise I'll work on my photography skills.  This picture doesn't do it justice!

Lemon Layer Cake 

White Butter Cake

2 1/2 cups cake flour, plus extra for pans
1 cup whole milk, room temp
6 large egg whites, room temp
1 1/2 teaspoons vanilla
1 3/4 cups sugar
4 teaspoons baking powder
1 teaspoon salt
12 tablespoons unsalted butter, cut into 12 pieces, softened but still cool

Technique:

1. Adjust an oven rack to the middle position and heat oven to 350.  Grease and flour two 9-inch cake pans and then line with parchment paper. 
2. In a medium bowl, whisk together the milk, egg whites, and vanilla. 
3. In a standing mixer, fitted with a paddle attachment (if you have one) mix the flour, sugar, baking powder, and salt at low speed until combined. 
4. With mixer at low, add the butter one piece at a time continuing to beat until the mixture resembles moist crumbs with no visible butter. 
5. Add all but 1/2 cup of the milk mixture and beat at medium speed until pale and fluffy. 
6. With the mixer at low speed, add remaining milk mixture then increase the speed to medium and beat for 30 seconds. 
7. Stop mixing and scrape sides of bowl, then mix another 20 seconds at medium speed. 
8. Divide batter evenly between the pans and lightly tap on the counter a few times to settle the batter. 
9. Bake at 350 for 20 – 25 minutes, rotating midway through baking, until a toothpick inserted in the center of each layer comes out clean. 
10. Cool cakes on a wire rack for 10 minutes, then run a small knife around the edges of the cake and flip out onto the wire rack.  Peel off parchment paper and turn cakes right side up to finish cooling completely before frosting, approximately 2 hours. 

Lemon Curd Filling

1 cup juice from about 6 lemons 1 teaspoon powdered gelatin
1 1/2 cups sugar
1/8 teaspoon salt
4 large eggs, plus 6 egg yolks (reserve whites for cake)
8 tablespoons unsalted butter, cut into 1/2 inch cubes and frozen

Technique:

1. Measure 1 tablespoon of lemon juice into a small bowl; sprinkle with gelatin over the top and set aside. 
2. Heat remaining lemon juice, sugar, and salt in a medium saucepan over medium-high heat stirring occasionally until sugar dissolves and mixture is hot, but not boiling. 
3. Whisk the eggs and yolks in a large bowl.  Whisking constantly, slowly pour the hot lemon sugar mixture into the eggs and return mixture to saucepan. 
4. Cook over medium-low heat, stirring constantly, until mixture registers 170 on an instant-read thermometer and is thick enough to leave a trail when stirring, approximately 4 – 6 minutes. 
5. Immediately remove the pan from heat and stir in gelatin mixture until dissolved. 
6. Stir in frozen butter until incorporated. 
7. Pour filling through a fine-mesh strainer into a bowl and lay sheet of plastic wrap directly on the surface and refrigerate until firm enough to spread, at least 4 hours. 

Classic 7 Minute Frosting

1 cup sugar
2 large egg whites, room temp
1/4 cup water
1 tablespoon lemon juice
1 tablespoon corn syrup

Technique:

1. Combine all ingredients in the bowl of stand mixer or a large heatproof bowl and set over a medium saucepan filled with 1 inch of barely simmering water. (Do not let bottom of bowl touch water.) 
2. Cook, stirring constantly, until instant-read thermometer registers 160, approximately 5 – 10 minutes. 
3. Remove from heat and transfer to stand mixer.  Beat on medium speed until soft peaks form, about 5 minutes. 
4. Increase speed to medium-high and continue beating until mixture has cooled to room temp and stiff peaks form, approximately 5 more minutes. 

Brittany’s Tips 

• For best results, read the directions all the way through once so you don’t miss little things like saving 6 egg whites from the lemon curd for the cake – thus one reason for my additional trip to the store for more eggs. 
• Remember baking is a science and every little step counts, so make sure to let your milk and egg whites come to room temp before baking, because it will make a difference. 
• When separating egg whites from yolks, have a separate bowl from the main mixture so if you get a little yolk in the whites, you won’t ruin the whole mixture, just that one egg. 
• Anytime you are pouring a hot mixture into eggs, make sure to do it very slowly and a little bit at a time, otherwise you run the risk of scrambling your eggs. 
• The double boiler technique can be scary for some, but as long as you make sure the water isn’t touching the bottom of the bowl and it’s just at a nice simmer, everything should turn out okay. 
• When checking temperatures with an instant-read therometer, make sure you aren’t touching the sides of the bowl with the probe, just the liquid mixture – you’ll get a much more accurate reading. 
• The best prep sequence for this cake is to make the lemon curd first, then the cake after a few hours.  Wait until the cake is assembled before making the 7 minute frosting. 
• To assemble, line the edges of a cake platter with strips of parchment to keep platter clean. Using a serrated knife, cut each cake horizontally into two even layers.  Place first layer on cake stand and spread approximately 1 cup of lemon filling evenly on the cake.  Repeat until cake is assembled.  Frost, remove parchment paper strips, and enjoy! 

Happy Baking!!