Special equipment: pastry bag with decorating tip and bowtie cookie cutter
For the cake batter: Preheat the oven to 325 degrees F. Line cupcake pans with 30 cupcake liners.
Sift together the flour, cocoa powder, baking powder, salt and baking soda in a large bowl and set aside. In the bowl of a stand mixer with a paddle attachment, cream the sugar and eggs until light yellow in color, about 3 minutes. Mix in the oil until combined. Add the sifted ingredients and mix until incorporated. Mix in the yogurt. Scrape down the sides of the bowl, add the port and vanilla and mix until incorporated.
Fill the cupcake liners three-quarters full with batter. Bake until an inserted toothpick comes out clean, about 25 minutes. Let the cupcakes cool 15 minutes, and then pull them from the pans and place on a cooling rack or baking sheet to cool completely.
For the buttercream frosting: In the bowl of a stand mixer with a whisk attachment, combine the egg whites and cream of tartar and whip at medium speed until frothy. Add 1 1/2 cups of the sugar and whip at high speed until stiff peaks form.
In a saucepan, stir the remaining 1/2 cup sugar into 1/2 cup water. Put a candy thermometer in the pan and place the pan over medium-high heat. When the simple syrup reaches the soft-ball stage (235 to 245 degrees F), immediately pour it into the egg whites while the mixer is on low speed. Once all the syrup is added, turn the mixer to high and whip until the bottom of the bowl is cool, about 15 minutes. Add the butter and whip until smooth and silky. Add the vanilla and mix until incorporated.
For the white chocolate shell: Melt the white chocolate in a double boiler. Turn each cupcake upside down and dip in the melted chocolate; set aside to harden.
To assemble: Put the frosting in a pastry bag with the desired decorating tip. Pipe one low swirl of frosting on top of each cupcake. Sprinkle with chocolate-covered cereal pearls.
Roll out the modeling chocolate with a rolling pin and cut into bowtie shapes. Place one on top of each frosted cupcake.
This recipe was created by a contestant during a cooking competition. It has not been tested for home use.