Japanese Christmas Cake
Following the events of the Meiji Restoration, Japan opened its doors to the world, and there was an influx of Western culture to Japan, including pastries and cakes as well as holidays like Christmas. In 1922, Fujiya, a western-style sweets maker, started producing Christmas Cakes and selling them through their shop in Ginza. Western-style desserts were considered an exotic luxury at the time, but by the 1970s, Christmas Cake had become as iconic as Santa Claus.
These days Christmas Cakes come in all shapes and sizes, but they’re most commonly a round layer cake made with layers of sponge cake, cream, and strawberries. To save time and effort, I’ve turned this version into a rustic roll cake, which only takes about ten minutes in the oven.
Why This Recipe Works
- By heating the eggs and sugar in a double boiler before whipping them it makes for a foolproof sponge that’s light and fluffy.
- Adding only a limited number of strawberries on the side and using the rest to top the cake, not only makes it easier to roll, it also prevents the inside from getting watery.
- Using cultured unsalted butter in the cake results in a moist buttery sponge cake.
About one percent of the Japanese population identifies as Christian, so Christmas is a secular holiday in Japan. Since the New Year’s holiday is the time to get together with family, Christmas is mostly celebrated with friends and significant others. Dining out is one popular option, and the two foods that are synonymous with Christmas are fried Chicken and Christmas Cake. Specifically, KFC has become an integral part of the Christmas experience here due to some clever marketing when they first came to Japan in the 1970s. 
Christmas cake is basically a Japanese-style Strawberry Shortcake. The difference is in the way it is decorated using Christmas motifs such as Santas made from sugar, plastic Christmas trees, and chocolate placards reading “Merry Christmas.”
Ideally, you want to use small strawberries with an intense strawberry flavor, good shape, and bright red color. I used two Japanese varieties for this one, including Sagahonoka for the inside and Amaou for the topping. 
The first thing is to make a sponge cake. It’s a génoise batter made by heating whole eggs with sugar before whipping the mixture until it is light and fluffy. There is no chemical leavening in this cake, so incorporating enough air into the eggs is a crucial part of getting the cake to rise properly. For my version, I also add some vanilla extract and butter in the batter for both flavor and tenderness.
Once the eggs have developed enough volume, a small amount of sifted cake flour is added to the batter and mixed in until there are no lumps. Because cake flour has a lower gluten content than other types of flour, you can thoroughly mix it into the batter without having to worry about the cake getting tough.
The batter goes into a parchment-lined jelly roll pan, and after the top is smoothed off, the pan is smacked against the countertop to force any large air bubbles to burst. This keeps the crumb of the cake consistent and avoids big craters on the surface of the cake.
Once the cake is baked, it needs to fully cool; otherwise, the cream will melt. You can speed this up by putting the cake in the fridge or freezer once it is no longer hot.
For the cream on the inside, you want to whip it until it holds firm peaks as you want it stay-put as you roll it. For the strawberries, I usually cut them in half, but depending on the size of your berries, you may need to quarter them.
Once the cake has cooled, it needs to be separated from the parchment paper, and then I like to trim about 2-inches of cake from one side at an angle. This allows you to roll the cake up without leaving a seam where the last layer of cake meets the roll.
To roll the cake, I just spread the cream across the entire top surface of the cake, line up the strawberries on one side, and roll it up, using the parchment paper to keep the roll tight. The tricky part is to apply enough pressure, so you don’t have gaps of air in your roll, but not so much pressure that you squeeze the cream out of the sides. Once it’s rolled, you’ll want to chill the cake in the fridge to set the cream.
To decorate the cake, I usually whip the cream a little softer than for the filling. This allows you to spoon dollops of cream onto the top of the cake like drifts of snow. Then it’s just a matter of arranging some whole strawberries and decorations you have on top.
Ingredients
for cake
- 1 teaspoon cultured unsalted butter (for buttering pan)
- 75 grams cake flour
- 4 large eggs
- 100 grams granulated sugar
- 1 teaspoon
- 50 grams cultured unsalted butter (melted)
to assemble
- 1 cup heavy whipping cream (at least 37% fat)
- 2 tablespoons powdered sugar
- 80 grams strawberries (4 small berries)
to garnish
- 1/2 cup heavy whipping cream
- 1 tablespoon powdered sugar (plus more for dusting)
- 120 grams strawberries (6 small berries)
- silver dragées optional
Steps
- Preheat the oven to 355 F (160 C)
- Line a 10.5 x 15.5 inch sheet pan with parchment paper, and use a teaspoon of softened butter to butter the paper.
- Sift the flour onto a piece of parchment paper and set aside.
- Break the eggs into a heat-safe bowl of an electric mixer and add the sugar and vanilla.
- In a pot that’s big enough to fit the bowl, heat a few inches of water until hot.
- Place the bowl in the hot water bath and mix gently until the egg reaches 100 degrees F (38 C) about the temperature of bathwater.
- Attach the bowl to the mixer and beat at high speed using the whisk attachment for 5 minutes.
- Turn down the speed to medium and slowly pour in the melted butter.
- When the butter has been fully incorporated, turn down the speed to low and add the flour. Continue mixing until there are no lumps of flour, but be careful not to overmix. You may need to stop the mixer once and scrape down the sides.
- Pour the cake batter into the prepared sheet pan and smooth off the top using an offset spatula or pastry knife. Smack the bottom of the pan against the countertop to force any large air bubbles to the surface.
- Bake for 10-12 minutes, or until the cake is set in the center.
- Let the cake cool on a rack until room temperature.
- Slice the tops off of 4 strawberries and then cut them in half.
- Using a whisk or electric mixer, whip 1 cup of heavy cream with 2 tablespoons of powdered sugar until it holds firm peaks. The cream should be stiff, but be careful not overwhip it, or it will get chunky.
- Peel the parchment paper away from the cake.
- Slice 2-inches (5cm) of cake off from the left side at an angle. This makes it easier to finish rolling the cake.
- Spread the whipped cream all over the top of the sponge cake (you don’t need to spread it on the cut surface).
- Spread the strawberries in a line about 2-inches from the right edge.
- Turn sheet, so the side with the strawberries is closest to you, and then use the parchment paper to roll the cake up and over the berries. Continue rolling the cake, being careful not the roll the parchment paper inside.
- When you’re finished rolling, wrap the extra parchment paper around the cake and then set the roll on a sheet pan with the seam at the bottom. Refrigerate for at least 1 hour.
- When the cream has set, unwrap the cake onto a flat surface and then trim off both ends of the roll.
- Dust the roll with powdered sugar and place the cake on your serving platter.
- When you’re ready to serve the cake, whip the remaining cream with the remaining powdered sugar until it forms soft peaks. You want the cream firm enough so it doesn’t run all over the place, but it should still be loose enough to pour off of a spoon.
- Slice the tops off of the remaining strawberries.
- Drop dollops of whipped cream off of a spoon onto the top of the cake to make mounds of snow.
- Top with the strawberries, and if you want, you can decorate your cake with sugar Santas and food-safe decorations like silver dragées.
