This Poppyseed Cake with Orange Curd and White Chocolate Buttercream is one of the most jaw-dropping gorgeous cakes I have ever made. It is tall and stately simply finished with sweetened dry orange slices that hint at the flavor of the filling. Spring is here and Easter is around the corner. While coconut cakes are popular for this holiday, I thought a change of pace would be perfect.
I found the orange slices with the dried fruit at Trader Joe's.
One of the easiest ways to finish a cake is with a cake comb. It has three variations and is used to simply comb the side of the cake after the final coat of buttercream. I have finished the bottom edge with a piped bead but that can easily be omitted if desired.
The Poppyseed Cake itself is easy to make. Each layer is about 1 ¼” tall, moist, and perfect. Poppyseeds add texture as well as interest to the cake itself. The layers can be made ahead, wrapped well and frozen for several weeks.
The intensity of orange curd makes just a little filling go a long way.
An Italian buttercream flavored with white chocolate finishes the cake. White chocolate can be tricky and difficult to melt if heated too much. I don’t suggest the microwave when melting white chocolate. Cutting the chocolate into small pieces and placing it in a double boiler over barely simmering water will yield perfectly melted white chocolate every time. Do not let the water boil or it can seize. This buttercream can be made weeks ahead and frozen or it can be stored in the refrigerator for about a week. Go here for how to make and reconstitute cold buttercream.
Orange Curd or the Poppyseed Cake
While the use of gelatin in the lemon and lime curd is not strictly necessary, the use of it here is definitely a necessity. This is a most interesting curd as when it is completely cooked, it is still somewhat liquid. Do not panic at this point (like I did). It will set up perfectly upon chilling. The use of lemon juice in addition to the orange juice and rind gives the requisite tartness to this curd. Microwave the lemon for 15 to 20 seconds and the orange for 30 seconds to make the juicing much easier as the fruit readily gives up its juice when the fruit is warm.
2 tablespoons lemon juice
1 teaspoon gelatin
6 egg yolks ( 100 grams or 3 ½ ounces)
½ cup sugar 100 grams or (3 ½ ounces )
1 ½ tablespoons orange rind
⅔ cup freshly squeezed orange juice
6 tablespoons butter ( 85 grams or 3 ounces)
Dissolve the gelatin in the lemon juice. Set aside.
Beat the egg yolks in a bowl to mix; whisk in the sugar. Add the orange juice; whisk to mix. Strain into the top of a double boiler. Add the orange rind and butter. Place over gently boiling water in the bottom of the double boiler and cook, stirring constantly, until the mixture reaches 172 degrees on a candy thermometer. Tear the dissolved gelatin into small pieces if it is completely set or simply add it if it is still somewhat liquid whisking it into the curd. Pour it into a storage container and cover directly with film. Poke a few holes in it and allow to cool, then refrigerate. This will last 10 days in a refrigerator and freezes well.
Thaw in the refrigerator a day or two ahead if frozen.
Yield: 1 ⅔ cup
3 cups cake flour (375 grams or 13 ½ ounces)
1 teaspoon baking powder
½ teaspoon baking soda
1 teaspoon salt
⅓ cup poppy seeds (40 grams or about 1 ⅓ ounces)
¾ cup unsalted butter softened to room temperature (170 grams, 6 ounces or 1 ½ sticks)
2 cups granulated sugar (400 grams or 14 ounces)
4 eggs room temperature
2 teaspoons vanilla extract
¼ cup water
¼ cup canola or vegetable oil
1 cup sour cream (225 grams or 8 ounces)
Preheat oven to 350°F. Spray the center only of 3 - 9” round pans with baking spray. Line with parchment and spray the center only. Set aside.
Whisk the flour, baking powder, baking soda, salt, and poppy seeds together. Set aside.
In the bowl of a mixer beat the sugar and butter together until light and fluffy.
Beat in the vanilla and two eggs until completely mixed. Add the last two eggs. Add the oil, beating well and then the water. The batter will become thicker at this point and emulsified.
Setting the mixer to low, beat in the flour mixture 4 times with the sour cream 3 times into the wet ingredients, starting with the flour and ending with the flour.
Divide the batter between the three pans (500 grams or 17 ½ ounces each).
Bake for 17 to 19 minutes. They will be very lightly browned and a tester will come out clean.
The cake layers can be frozen, then wrapped well and held up to a month if making ahead.
White Chocolate Buttercream
4 ounces white chocolate, melted (114 grams)
½ cup water
⅔ cup sugar (130 grams or 4 ½ ounces)
½ cup egg whites (about 4 whites from large eggs, 130 grams or 4 ½ ounces)
½ teaspoon cream of tartar
3 tablespoons sugar (38 grams or 1 ⅓ ounces)
2 teaspoons vanilla
1 ½ cups +3 tablespoons unsalted butter (380 grams, 13 ½ ounces or 3 ⅓ sticks), softened but not runny
This small amount of sugar syrup comes to temperature very fast after it reaches 220 degrees. Watch it carefully to prevent it from going too high. Place the water in a small saucepan. Add the sugar and stir; bring to a boil. Wash down the sides of the pan with a brush dipped in cold water to prevent crystallization. Boil to 250 degrees on a candy thermometer. You will probably need to tilt the pan to have enough liquid to measure the temperature.
Simultaneously, place the egg whites and cream of tartar in a mixing bowl fitted with the whisk attachment. Beat until soft peaks form. Gradually add the 3 tablespoons sugar. Beat until stiff on high, then immediately turn the mixer down to low or #1 to hold them. When the sugar syrup is ready, raise the mixer to medium and slowly pour it over the whites. Aim for between the whisk and the side of the bowl. Do not pour it over the whisk or it will not mix into the egg whites. Also, make sure it is poured in slowly to prevent the syrup from sinking to the bottom of the bowl, from where it cannot be incorporated. Beat until completely cool.
Add the butter a couple of tablespoons at a time. Do not add more butter until the preceding butter is incorporated. When all the butter is in, add the extract and beat to incorporate. When the buttercream is cool, add the melted white chocolate. Continue beating until very light in texture.
Thaw it in the refrigerator several days before using.
Assembly of the Poppyseed Cake
Orange curd, thawed if frozen
½ cup heavy cream
3 layers of poppyseed cake, thawed
White chocolate buttercream, reconstituted if cold.
Sweetened Dry Orange slices if using
Whisk the orange curd to smooth it. Beat the cream to medium peaks. Fold into the curd. Set aside.
Although this cake can be filled without a mold, it is easier if a 9x3” cheesecake pan or spring mold is used.
Place one layer of cake in the bottom of the pan. Fill to within about ½ inch of the edge with half of the lightened orange curd. Place a second layer on top. Add the remaining curd and top with the last layer of cake. Cover with plastic wrap and chill several hours or overnight.
Release the cake by placing the cake on a wide can.
Slide the side down. Transfer the cake to a cake board by placing pancake turners under each side of the bottom of the cake.
LIft the cake and place it on a cake board.
Reconstitute the buttercream if needed. Undercoat the cake, chill to set. Finish the Poppyseed cake with another coat of buttercream. Comb the sides of the cake. Set aside.
If using the sweetened dry orange slices, cut from the edge to the middle of each slice. Heat briefly in the microwave to make them flexible. Twist them immediately and place them on a plate to cool. Whatever you do, don’t place them on the cake immediately as I did in this picture. The hot orange slice will melt the buttercream.
Place the cooled slices on the cake while the buttercream is still soft. Chill the Poppyseed Cake.
The Poppyseed Cake can be made entirely the day before serving and held in the refrigerator. Refrigerate any leftover cake for several days.
Yield up to 20 servings.