Chocolate Cake with Strawberry Marshmallow Frosting

 

The Little Prince has a book called Cook It! The Dr. Seuss Cookbook for Kid Chefs, by Daniel Gercke. He asked me to make a specific recipe from it for his birthday, the cake called Cat in the Bath Birthday Cake. The name isn’t very descriptive, though, hence my title of Chocolate Cake with Strawberry Marshmallow Frosting. The first thing I have to say is that this isn’t a recipe for kids – the frosting is a grown-up undertaking, for sure. As a matter of fact, I couldn’t help but notice that in this official video, the chef makes the frosting while her kid is off somewhere else! It was so worth it, though, because the frosting was divine! 

The only thing that I would change would be to heat the sugar and strawberry purée to 230 °F, like in a seven-minute frosting, while whisking the egg whites with the cream of tartar and salt separately, then drizzling the syrup into the egg white mixture. My frosting was runny, like in the video, come to think of it; I would have preferred a stiffer consistency, like in the photo in the cookbook. The seven-minute frosting method seems better to achieve this. 

As a reminder, to make a lactose-free buttermilk substitute, you can use about 1 tablespoon of vinegar or lemon juice in 1 cup of lactose-free milk, or use lactose-free plain yogurt thinned out with some lactose-free milk. I also added some precisions regarding the size of the bowls to use. 

For the cake 

2 ½ oz. bittersweet chocolate, chopped 

1 ¼ cups hot decaffeinated coffee (or water) 

2 ½ cups sugar 

2 cups unsweetened Dutch-processed cocoa powder 

2 ¼ cups all-purpose flour 

1 ½ tsp. baking soda 

1 tsp. kosher salt 

¾ tsp. baking powder 

1 ¼ cups lactose-free buttermilk substitute (see note above)

2/3 cup neutral vegetable oil 

1 tsp. vanilla extract 

3 large eggs 

For the frosting 

8 oz. fresh strawberries, hulled 

2 large egg whites 

1 ½ cups sugar 

1 pinch of cream of tartar 

1 pinch of kosher salt 

sprinkles (optional) 

For the cake 

Preheat the oven to 325 °F. Grease three 9-inch round cake pans; line the bottom with parchment with parchment paper and grease again. 

In a medium microwave-safe bowl, microwave the chocolate on medium-low power in 30-second intervals, stirring in between, until melted. Whisk in the coffee until completely combined, then set aside to cool. (I did this in a double-boiler.) 

In a large-ish bowl (not your largest), whisk together the sugar and cocoa powder until there are no lumps. Whisk in the flour, baking soda, salt, and baking powder. 

In a small bowl, whisk together the buttermilk substitute, oil, and vanilla. 

In another large bowl (this time, your largest), beat the eggs with a handheld mixer until pale and frothy, about 3 minutes. Scrape in the cooled chocolate mixture and beat to combine. Pour in one-third of the buttermilk mixture and beat until just combined. 

Pour in one-third of the flour mixture and beat until just combined, then scrape down the sides of the bowl. Repeat two more times, alternating the buttermilk and flour mixtures, mixing just until the batter is smooth and free of lumps. 

Divide the batter among the prepared pans and bake until the tops spring back when touched and a toothpick inserted in the center comes out clean, 30 to 35 minutes. Transfer the pans to a wire rack to cool completely. 

When the cakes are cool, run a thin offset spatula or butter knife around the edges of the pans to loosen them, then invert them and remove the parchment paper. Turn the cakes right side up and trim the tops with a serrated knife so the layers are even (I didn’t bother). 

When the cakes are trimmed, move on to the frosting. (Don’t make the frosting ahead of time; it doesn’t stay spreadable for very long. If needed, the cakes can be baked a day ahead and stored in the refrigerator, tightly wrapped with plastic wrap.) 

For the frosting 

In a blender, purée the strawberries until very smooth, then press through a fine-mesh sieve. You should end up with 2/3 cup of strawberry purée. 

Heat 1 inch of water in a medium pot until simmering. 

(This is where you should read the note above regarding the method for the frosting – the following instructions are as they originally appeared in the cookbook.) In the metal bowl of a stand mixer, whisk together the strawberry purée, egg whites, sugar, cream of tartar, and salt. Place the bowl over the simmering water (without letting it touch the water) and whisk constantly until the sugar has dissolved. (The bowl will heat up, so use an oven mitt to hold it.) Transfer the bowl back to the mixer and whisk on high speed until thick and glossy with medium peaks, 3 to 5 minutes. Use the frosting immediately. 

Place one cake layer on a serving plate or sake stand and spread some of the frosting on top. Repeat with the remaining layers, stacking them on top of each other. Spread the frosting on the sides of the cake and smooth the top and sides, making swirls and swags if you like. Top with sprinkles, if using. This cake is best eaten the day it’s made. (Personally, I kept the leftover frosting in the fridge to use on other stuff, and I regret nothing. It was fantastic!)