Green Tea & Strawberry Prinsesstårta (Daring Bakers' Challenge)

Once again, the Daring Bakers' Challenge has introduced me to an awesome cake that I had no idea even existed. This cake is known as Prinsesstårta (Princess Cake) and its back-story is just as adorable as the cake itself. It was originally called Grön tårta (Green Cake), but the name was changed because it was a particular favorite of the daughters of  Prince Carl, Duke of Västergötland. Traditionally, the cake is covered in green marzipan and topped with a pink marzipan rose.

Korena of Korena in the Kitchen was our May Daring Bakers’ host and she delighted us with this beautiful Swedish Prinsesstårta!

The cake traditionally has three layers of plain sponge cake, two layers of vanilla custard, a layer of raspberry jam, and a large layer of whipped cream.

However, when I first saw a picture of this cake, with its green outside and pink rose, my first thought was of green tea and strawberries. So, I decided to do a bit of a variation on the traditional Prinsesstårta: three layers of green tea sponge cake, two layers of vanilla and strawberry custard, one layer of strawberry filling, and a layer of lightly-strawberried whipped cream.

There are a lot of components to this cake, but none of them are very difficult or time-consuming. It's also very easy to spread the work over a couple days. The strawberry filling, custard, and even the sponge cake can be made a day ahead of time. I found the most difficult part to be covering the cake with marzipan. I've covered a cake with fondant before (my Champagne & Strawberries Cake), and had some success, although there were small wrinkles and tears. I found that that I had a harder time with marzipan - there were more, larger wrinkles. Also, the cake layers are clearly visible underneath the thin marzipan layer. On the other hand, marzipan is a million times more delicious than fondant, so the wrinkles are totally worth it.

This is a very tasty cake. It's not a very "cakey" cake - that is, there are a lot of things in it besides the sponge cake itself. I really enjoyed it. The strawberry and green tea flavors were excellent, and the cake was very light and airy. Perfect for a princess or just a plain old commoner like myself!

Green Tea & Strawberry Prinsesstårta
Adapted from Semiswede. Makes a 6-inch round cake.

Strawberry Filling

Ingredients
6 ounces frozen or fresh strawberries, thawed (if frozen)
2 teaspoons cornstarch
1 tablespoon sugar

Method

1. Puree the strawberries in a food processor. Press the strawberry slurry through a strainer and into a small saucepan.
2. Add the cornstarch and sugar to the saucepan, and heat on medium heat until the mixture thickens. Remove from heat.
3. Cover and refrigerate for several hours until completely cold.

Vanilla & Strawberry Custard

Ingredients
½ cup heavy cream, divided
2 egg yolks
1 tablespoon cornstarch
1 tablespoon sugar
1 teaspoon vanilla extract
2 ounces fresh strawberries, cut into small pieces

Method

1. Whisk together ¼ cup of the cream, the egg yolks, the cornstarch, and the sugar in a medium bowl.
2. In a small, heavy-bottomed saucepan, heat the remaining cream (¼ cup) just until boiling.
3. Slowly whisk the hot cream into the egg/starch/sugar mixture to temper the eggs.
4. Transfer the mixture back to the saucepan and heat on medium-low until it thickens, whisking constantly (seriously, don't leave it even for a minute or it will get super thick and curdle-y). 
5. Once it's thickened to a custard-like consistency, remove from heat.
6. Whisk in the vanilla and transfer to a bowl or tupperware.
7. Place plastic wrap directly on the surface of the custard to prevent a skin from forming and refrigerate for several hours until completely cold.
8. Just before assembling the cake, mix the fresh strawberries into the custard.

Green Tea Sponge Cake

Ingredients
fine dry breadcrumbs for the pan (I'm think flour would work as well)
2 eggs
½ cup sugar
¼ cup all-purpose flour
¼ cup cornstarch
½ teaspoon baking powder
1 tablespoon matcha (I used Maeda-En Matcha - Culinary Quality)
dash of salt

Method

1. Preheat your oven to 350° F. Line the bottom of a 6-inch round springform pan with parchment paper. Grease the pan and paper and coat with breadcrumbs. Tap out the excess. I think a non-springform pan would work, but you want to make sure the sides are nice and high (3 inches).
2. Beat the eggs and sugar in a medium bowl at medium speed until the eggs have tripled in volume and the mixture falls from the beaters in thick ribbons (about 5 minutes).
3. In a small bowl, sift together the flour, cornstarch, baking powder, matcha, and salt.
4. Transfer the dry ingredients into the egg/sugar mixture. With a balloon whisk, mix the ingredients while trying to keep as much air in the mixture as possible.
5. Pour the mixture into the prepared pan. Bake for 30-40 minutes, or until the top springs back when touched.
6. Remove and allow to cool for 10 minutes. Run a knife around the edge of the pan and remove the springform sides. Transfer the cake to a cooling rack and allow to cool to room temperature.

Light Strawberry Whipped Cream

Ingredients
1 cup heavy whipping cream
2 teaspoons strawberry filling (see recipe above)

Method

1. In a medium bowl, whip the whipping cream until soft peaks form.
2. Add the strawberry filling and whip until stiff peaks form.

Assembly

1. Cut the sponge cake into three even layers (I like using a cake leveler to do this).
2. Spread the strawberry filling evenly onto the bottom layer of the cake.  On top of this, spread half of the vanilla & strawberry custard.
3. Place the top cake layer on top (saving the middle layer for later). Spread the remaining custard on top evenly.
4. Set aside about ½ cup of the strawberry whipping cream. With the rest, shape it into a nice round mound on top of the custard.
5. Place the last cake layer (the middle one) on top of the whipping cream. Try not to smush the whipping cream - you want to keep the top nice and round. Try to tuck in the sides of the cake as much as possible so that the round top transitions seamlessly into the sides. I ended up cutting off some of the cake corners with a knife to smooth this out.
6. Use the remaining whipping cream to "frost" this cake - almost as you would with a crumb coat. Your goal is to get everything smooth so that the marzipan will look good.
7. Transfer the cake to the refrigerator while you prepare the marzipan.
8. Dye 7 ounces of marzipan (I used store-bought, but you can make your own) light green (if desired). Roll the marzipan out into a circle on a surface dusted with powdered sugar until it is very thin (⅛ inch thick).
9. Remove your cake from the refrigerator. Roll the marzipan around a rolling pin and transfer onto the cake. Smooth out the marzipan as much as possible and trim off the excess.
10. You can use the excess marzipan to cut out pretty leaves and top with a pink marzipan rose if desired!