Please allow me to introduce my 27th birthday cake–The Coconut Passion Fruit Cake.
Coconut Cake with Passion Fruit Curd and Passion Meringue Buttercream
adapted from several sources
For Coconut Cake:
3 sticks (1 1/2 cups) unsalted butter, at room temperature
2 1/2 cups granulated sugar
4 large whole eggs
4 large egg whites
3 tsp. pure vanilla extract
1 1/2 cups unsweetened coconut milk
2 cups packed unsweetened shredded coconut
3 1/2 cups all-purpose flour
4 tsp. baking powder
1 tsp. salt
For Passion Fruit Curd:
1/2 cup unsweetened passion fruit concentrate (not sweetened juice concentrate)
Juice of 1/2 lemon
2 egg yolks
1/2 cup sugar
2 Tbsp. cornstarch
Pinch of salt
4 tbsp. cold unsalted butter, cut into 16 pieces
1/2 cup heavy cream, optional–to lighten the curd a bit
For Passion Fruit Buttercream:
4 large egg whites
1/4 tsp. cream of tartar
3/4 cup white sugar
2 Tbsp. water
1 tsp. vanilla
3 sticks unsalted butter, chilled and cut into tablespoon-sized pieces
unsweetened passion fruit concentrate, optional
For Coconut Cake:
Preheat oven to 350 degrees F.
Grease two 9″ round cake pans with shortening. (If using 8″ rounds, make sure they are 3″ high or the batter will overflow.) Cut a wax paper round to fit in the bottom. Grease the paper round. Dust the pans with flour, tap out excess.
In the bowl of a food processor, pulse the coconut until finely chopped. Set aside.
Using a stand mixer with a paddle attachment, cream butter and sugar together until very light and fluffy, at least 5 minutes. (Don’t skimp on this step!)
Lightly beat the whole eggs and egg whites together and drizzle into the creamed mixture while the mixer is running at low speed. Turn mixer up to medium speed and beat for another 30 seconds. Turn mixer off and scrape down sides of the bowl and the paddle.
In a large bowl, whisk together the flour, baking soda, salt, and reserved chopped coconut. Add 1/3 of the flour to the creamed mixture, beat to combine. Add 1/2 of the coconut milk and beat. Add half the remaining flour, beat. Add the rest of the coconut milk, beat. Finish with the last bit of flour. Beat just until combined–careful not to overbeat. Use a large spatula to scrape down the sides of the bowl and stir batter to make sure there are no streaks of flour or butter that aren’t fully mixed.
Transfer the batter to the prepared cake pans.
Bake until tops are golden and a cake tester inserted into the center comes out clean. Depending on the size and depth of pan, this may take anywhere from 35 to 45 minutes, or longer. Start checking after cakes for doneness after 35 minutes.
Let the finished cakes cool in the pan for 10 minutes. Run a thin knife around the edge to loosen the cakes. Turn the cakes out onto a wire cooling rack to finish cooling.
For Passion Fruit Curd:In a small saucepan, whisk together the sugar and cornstarch. Add the passion fruit concentrate, lemon juice, and egg yolks. Whisk well. Gently heat the mixture over medium heat, being careful not to let it boil and stirring constantly, making sure to get the bottom and corners of the pan. Cook until mixture thickens–about like yogurt. Remove from heat and vigorously whisk in the cold butter pieces. The curd will change to a lighter color and get thicker.
Strain the curd through a fine mesh sieve set over a clean bowl. Press plastic wrap directly on the surface of the curd. Chill for several hours, or until ready to use. Keeps about 3 days.
If using the heavy cream–
Beat the heavy cream to stiff peaks. Fold into the curd and chill until ready to use.
For Passion Fruit Buttercream (click here for a tutorial and an alternate recipe.)
In the bowl of a stand mixer fitted with the whisk attachment, beat the egg whites on low until foamy. Add the cream of tartar. Turn speed up to medium-high and beat until stiff peaks form.
Meanwhile, in a small saucepan bring sugar and water to a boil. Clip a candy thermometer to the side of the pan. Wash sides of pan down with a brush dipped in warm water to prevent crystallization. Cook syrup to 240 degrees F, or soft ball stage.
With the mixer running on medium speed, slowly drizzle the hot syrup down the side of the bowl. When all the syrup has been added, turn mixer up to high speed and continue beating for 3 minutes, or until steam no longer rises from the bowl.
Add the chilled butter one piece at a time, while continuing to beat. Add the vanilla extract. After adding the vanilla, add about 1/4 cup passion fruit concentrate. Continue beating until smooth. The buttercream will look curdled, continue beating until it comes together and becomes smooth and shiny.
Either use immediately on a cooled cake, refrigerate for about 1 week, or freeze up to several months.
Buttercream will need to be brought to room temperature and beaten again in the mixer to return it to proper consistency before using.
My note: I added a little too much concentrate and it was really strong and sour. To correct the problem, I ended up adding about 1 cup of powdered sugar. It did change the texture a bit, but was still very good.
To Assemble Cake:
Place first cake layer on the serving platter.
Top with 2nd layer.
Repeat with remaining curd and cake layer.
Chill for about 30 minutes to set the curd.
Cover the entire cake with a thin layer of the buttercream to create a crumb coat. (A crumb coat helps seal in any crumbs and makes the finished layer of icing go on easier and look nicer.)
Chill cake for an additional 30 minutes.
Spread the buttercream evenly over the cake. Pipe any remaining buttercream onto the cake, or decorate as desired.