Marble Sheet Cake

Marble Sheet Cake - made December 15, 2016, modified from The Cookies & Cups Cookbook by Shelly Jaronsky

While I was still enamoured of my latest baking book, I tried another recipe from it. I like marble cake okay. I like chocolate, I like vanilla, and I don't mind the two swirled together. I normally don't make marble cake though as it seems like it's a bit of a pain in the ass to have two different batters when one would do just fine. Plus, I've never really had a marble cake that was as good as having a plain vanilla cake or a plain chocolate cake on its own.

Vanilla Cake Batter

But I was in the mood for a "sheet" cake and this uses up some of the milk I had. A typical marble cake has you making the plain vanilla batter first then you separate the batter and add some kind of chocolate to half of it so that you end up with separate chocolate and vanilla batters that you then swirl together. Sometimes the chocolate addition is melted chocolate and sometimes it's cocoa powder. For this recipe, I was glad to see that while it does use cocoa powder, which tends to give a richer chocolate flavor, it also adds hot water to provide more liquid to the batter. That's exactly what you want when you use cocoa. Cocoa tends to dry out batters so when you use it, it's good to have additional liquid to have a more moist cake.

Swirled in the chocolate cake batter

Post-baking, pre-frosting

All in all, this cake was pretty good. I'm still fairly indifferent to marble cakes though. The vanilla cake portion was good, the chocolate cake portion was good. Swirled together, one didn't stand out more than the other in terms of flavor. The cake texture was quite nice though, nice and uh, well, cakey.

This recipe makes too much frosting if you make it in a 9 x 13 pan like I did instead of a sheet pan so you might want to cut the frosting recipe in half if you don't want a thick layer of frosting. What's pictured is about as thick as I like my frosting layer to be.

Cake
1 cup (2 sticks) salted butter, room temperature
1 1/2 cups granulated sugar
2 large eggs
2 teaspoons vanilla extract
1 tablespoon baking powder
1 teaspoon kosher salt
2 1/2 cups all-purpose flour
1 cup whole milk
1/4 cup unsweetened cocoa powder
1/4 cup hot water

Frosting
1/2 cup (1 stick) butter, cubed
1/4 cup unsweetened cocoa powder
1/4 cup plus 2 tablespoons whole milk
2 teaspoons vanilla extract
5 cups powdered sugar

1. Cake: Preheat the oven to 325 degrees F. Line a 9 x 13 pan with foil and lightly spray with nonstick cooking spray.
2. In the bowl of a stand mixer fitted with the paddle attachment, mix the butter and granulated sugar on medium speed for 2 minutes. Add the eggs, vanilla and salt and continue mixing on medium speed until smooth, scraping down sides of the bowl as necessary.
3. Turn the speed to low and add the baking powder and one-third of the flour, followed by half the milk, beating after each addition. Repeat with remaining flour and milk, ending with the final third of flour. Mix until just combined, scraping down the sides of bowl to keep batter even-textured.
4. Measure out 1 cup of batter and transfer to a medium bowl. Add the cocoa powder and hot water to the 1 cup batter and stir until evenly combined to make chocolate batter.
5. Spread the vanilla cake batter into the prepared pan. Drop the chocolate batter on top of the vanilla batter by the spoonful and, using a knife, swirl the chocolate into the vanilla. Do not overmix; you want the batters swirled together, not combined.
6. Bake for 25 minutes or until a toothpick inserted near the center comes out clean or with a few moist crumbs. Transfer the pan to a wire rack to cool slightly.
7. Frosting: While cake is baking, make frosting. In a large saucepan, combine the butter, cocoa powder, and milk and heat over medium heat until melted and smooth. Remove the pan from the heat and whisk in the vanilla and powdered sugar. Add powdered sugar one cup at a time, mixing until smooth and only adding enough to achieve the desired taste and consistency.