Lemon Cake with Lemon Curd Filling and Real Raspberry Buttercream

In my last post, I showed you a little trick for filling a cake with lemon curd. Now you can put it into practice and make this special cake with the delicious combination of lemon and raspberry. It's a great summertime cake - the flavors are light and refreshing.

Cake...filling...buttercream...homemade raspberry puree...it sounds like a lot of work. It is. Baking from scratch almost always is. All those bowls and strainers (stuck with raspberry seeds! ugh!) and pots to wash - that's the part I could do without.  But the work is all worth it once you taste the result of your efforts.

Here's a tip...if you have freezer space, it helps to make more than you need and freeze the rest, for quick assembly of defrosted components. No bowls or strainers or pots to wash the next time around. Or use the freezer to space out the work over a week's time, making each component as it is convenient.

Make more puree than you need, then freeze the leftover puree in 1/4 cup portions and save yourself from making puree each time you make raspberry icing, or raspberry ice cream, or raspberry sauce. I poured 1/4 cup of puree into each section of a muffin tin, froze it, then transferred the puree chunks to a plastic baggie for long term freezer storage. If I could find raspberry puree in the store, I would definitely consider buying it.

You can certainly freeze the cake layers. I do that anyway, whether I'm using the cake the next day or the next month. I don't recommend freezing cake longer than a month, however.

You can freeze Swiss meringue buttercream. Freeze it with only the vanilla added and add the raspberry puree when re-whipping the icing after it comes to room temperature.

I've heard you can even freeze lemon curd, although I've never tried it. Have you?

The photo below is not an actual slice from the cake above, but I wanted to show you what the inside of a lemon curd-filled cake looks like. See where I made the "dam" of icing when I filled the cake? A lot of work? Yes. Delicious? Definitely yes!

Lemon Cake

adapted from Sky High: Irresistible Triple Layer Cakes by Alisa Huntsman

3 cups cake flour
2 cups sugar
4 1/2 teaspoons baking powder

1 tablespoon lemon zest
1/2 teaspoon salt
2 sticks plus 2 tablespoons (9 ounces) unsalted butter at room temperature
1 1/3 cups milk
5 egg whites
1 tablespoon vanilla extract

Preheat the oven to 350 degrees F. Spray 3 8" cake pans with cooking spray, line the bottoms with parchment and spray the parchment.

Place the flour, sugar, baking powder, lemon zest and salt in a large mixer bowl. With the mixer on low speed, blend well. Add the butter and 1 cup of the milk and mix to blend. Raise the mixer speed to medium and beat until the batter is light and fluffy, about 2 minutes.

In a mixing bowl, whisk the egg whites with the vanilla extract and the remaining 1/3 cup milk. Add this to the batter in 2 or 3 additions, scraping down the bowl well and mixing only to incorporate. Divide the batter evenly among the pans. Bake for about 30 minutes, or until a cake tester inserted in the center comes out clean. Allow the cake to cool in the pans for 10 minutes, then invert them onto wire racks and cool completely, about 1 hour.

Wrap each cake layer with a double layer of plastic wrap and freeze for at least one hour or up to one month.

Lemon Curd
adapted from The Secrets of Baking by Sherry Yard
makes about 2 cups

2/3 cup sugar
2 tablespoons finely chopped or grated lemon zest
3 large eggs
4 large egg yolks
3/4 cups lemon juice, or 1/2 cup lemon juice and 1/4 cup lime juice
8 tablespoons unsalted butter, cut into 1/2-inch cubes

Fill a medium saucepan with about 2 inches of water and bring to a simmer. Combine the sugar and lemon zest in a food processor and pulse for about one minute. Combine the lemon sugar, eggs, and egg yolks in a medium heatproof bowl such as a stainless steel mixing bowl and whisk together for 30 seconds. Place the bowl over the simmering water and immediately begin whisking and stir until the sugar is dissolved. Add the lemon juice and continue to cook and stir with a rubber spatula to scrape the bottom of the bowl, until the curd has thickened and reached a temperature of 160 degrees F.

Rinse and dry the bowl of your food processor. Using a mesh strainer, strain the curd into the food processor bowl. Pulse the food processor while you add the butter a piece at a time, until the texture is homogenous. Transfer the curd to a container with a lid and place a piece of plastic wrap directly on the surface of the lemon curd. Allow the curd to cool completely and then place the lid on your container and place it in the refrigerator to chill for at least 2 hours or up to 5 days.

Raspberry Swiss Meringue Buttercream

6 ounces egg whites

10.5 ounces granulated sugar

1/2 teaspoon salt

16 ounces (4 sticks) unsalted butter, at cool room temperature, cut into tablespoon-sized pieces

2 teaspoons vanilla

1/4 cup raspberry puree

Place 2 inches of water in a medium saucepan and bring the water to a simmer. Choose a saucepan that your mixer bowl will fit on top of without touching the water. In your mixer bowl, place the egg whites, sugar, and salt and whisk to combine. Place the bowl over the simmering water and continue to whisk until the sugar is fully dissolved and the mixture is very hot to the touch, about 130-140 degrees F.

Remove the bowl from the double boiler and place on your stand mixer fitted with a whisk attachment. Whisk at medium-high speed until the outside of the mixer bowl is room temperature. It is very important that the meringue be completely cool before adding the butter.

Add the butter, a tablespoon at a time, letting each tablespoon disappear before adding the next. After all the butter has been added, switch to the paddle attachement and beat until the mixture becomes fluffy and thick. This could take up to an additional 5 minutes or so. The mixture will go through a stage where it looks curdled before it reaches the proper consistency.

Add the vanilla and the raspberry puree and beat until completely combined, about a minute.

Raspberry Puree

a bag of frozen raspberries (a gallon sized bag yielded about 2 cups of puree)

a sprinkling of sugar

Place the rasperries and sugar in a saucepan and bring them to a simmer. When the raspberries are softened and liquidy, pass the mixture through a strainer (I used a chinois) to remove the seeds, trying to get as much of the seedless pulp and liquid as possible through the strainer by pressing on the solids with a spatula or spoon. Return the strained liquid to the saucepan and reduce the liquid so that it becomes a little thicker and has a syrupy consistency. Pour 1/4 of the liquid into each cup of a muffin tin and freeze. (Reserve 1/4 cup if you will be using it right away. Let it come to room temperature before adding to the icing.) Transfer the frozen puree portions to a plastic bag for long term storage in the freezer.