Passion Fruit and Orange Fluffy Sponge Cupcake with Marshmallow Vanilla Frosting

By Whisk

Most people's favorite cake flavor is chocolate, but I love vanilla. And this one contains passion fruit (my all-time favorite fruit), orange and vanilla.

I've been playing around with baking cakes in different fruits lately. This time, I thought it would be fun to bake the vanilla white cake inside an orange shell so that the shell would infuse the cake.

Ingredients

• For the Orange Shells:
• 12 orange shells (I used clementines)
• For the Cupcakes:
• 3 egg whites (about 6 tablespoon)
• 1/4 teaspoon cream of tartar (optional, but it will help stabilize the egg whites when beaten)
• 3/4 cup flour
• 1/2 teaspoon baking powder
• 1/4 teaspoon salt
• 3 egg yolks (about 1/4 cup)
• 3/4 cup sugar
• 2 1/2 tablespoon cold water
• 1 teaspoon vanilla
• 1 teaspoon passion fruit, scooped (straining the seeds is optional)
• 1 teaspoon freshly squeezed orange juice
• For the Frosting:
• 1 cup sugar
• 1/2 cup water
• 4 large egg whites, at room temperature
• 2 teaspoons vanilla
• 2 teaspoons passion fruit, scooped (straining the seeds is optional)
• 2 teaspoons freshly squeezed orange juice

Details

Adapted from whiskblog.com

Preparation

Step 1

To prepare the orange shells: Slice off the top of the orange and use a grapefruit spoon to clean it out. Center a rack in the oven and preheat the oven to 250°F. Bake the shells for 1 hour, until they are dried out. Transfer the orange shells to a cooling rack and let cool to room temperature.

To get ready for the cupcakes: Center a rack in the oven and preheat the oven to 325°F.

To make the cupcakes: Sift together the flour, baking powder and salt.

Working with a stand mixer, preferably fitted with a whisk attachment, whisk the egg whites and cream of tartar (if using) until soft peaks form.

In another bowl, working with a stand mixer fitted with the paddle attachment, beat egg yolks until thick and lemon colored. Gradually, beat in sugar.

In a small bowl, mix the water, vanilla, passion fruit, and orange.

Reduce the mixer speed to low and add the dry ingredients alternately with water and flavorings, adding the dry ingredients in 2 additions and the water mixture in 1 (begin and end with the dry ingredients). Scrape down the sides of the bowl as required and mix only until the ingredients are absorbed into the batter. The batter will be thick.

Using a rubber spatula, fold the egg whites into the cupcake batter in 3 additions.

Using a piping bag, fill the cupcake shells (or orange shells) ¾ full.

To bake the cupcakes: Bake for 25-30 minutes, until the cupcakes are golden on top and a thin knife inserted into the center comes out clean. Transfer the cupcakes to a cooling rack and let cool to room temperature. When cool, the cupcakes can be wrapped and kept at room temperature overnight.

To make the frosting: Combine the sugar and water in a small saucepan. Boil the mixture until it reaches 248˚F (120˚C) on a candy thermometer.

While the sugar is melting, working with a stand mixer, preferably fitted with a whisk attachment, whisk the egg whites until soft peaks form.

Reduce the mixer speed to medium. While beating the egg whites, carefully drizzle the hot syrup into the bowl, pouring it between the spinning beater(s) and the sides of the bowl. Increase the mixer’s speed to high and beat the egg whites until cool (but not too much or the mixture will separate). Frost the cupcakes and drizzle with reserved passion fruit.