Chocolate sheet cake

By America’S Test Kitchen The Associated Press

This chocolate sheet cake requires that you use Dutch-processed cocoa powder. What exactly is that? A process called Dutching, which was invented in the 19th century by a Dutch chemist and chocolatier named Coenraad Van Houten, raises cocoa powder’s pH level, which gives the cocoa a fuller flavour and deeper colour. Dutch-processed cocoa (sometimes called “alkalized” or “European- style” cocoa) is the best choice for most baked goods. Using a natural (or “unalkalized”) cocoa powder results in a drier cake. Follow this recipe with your kids.
Servings: 15
Start to finish: 1 hour, 15 minutes (Inactive time: 1 hour, plus cooling time)
Ingredients Needed:Vegetable oil spray
1 1/2 cups sugar
1 1/4 cups all- purpose flour
1/2 teaspoon baking soda
1/2 teaspoon salt
1 1/3 cups bittersweet or semisweet chocolate chips
1 cup whole milk
3/4 cup Dutch-processed cocoa powder
2?3 cup vegetable oil
4 large eggs
1 teaspoon vanilla extract
Milk Chocolate Frosting (recipe follows)
Gather Cooking Equipment:13-by-9-inch metal baking pan
Medium bowl
Large saucepan
Rubber spatula
Oven mitts
Cooling rack
Icing spatula
Chef’s knife
Start Cooking!
Adjust oven rack to middle position and heat oven to 325 F. Spray bottom and sides of 13-by-9- inch metal baking pan with vegetable oil spray.
In medium bowl, whisk together sugar, flour, baking soda, and salt.
In large saucepan, combine chocolate chips, milk, and cocoa. Place saucepan over low heat and cook, whisking often, until chocolate chips are melted and mixture is smooth, about 5 minutes.
Turn off heat. Slide saucepan to cool burner and let mixture cool slightly, about 5 minutes.
Add oil, eggs, and vanilla to saucepan with chocolate mixture and whisk until smooth, about 30 seconds.
Add flour mixture and whisk until smooth, making sure to scrape corners of saucepan.
Use rubber spatula to scrape batter into greased baking pan and smooth top (ask an adult for help because saucepan will be heavy).
Place baking pan in oven. Bake until toothpick inserted in centre comes out with few crumbs attached, 30 to 35 minutes.
Use oven mitts to remove baking pan from oven (ask an adult for help). Place baking pan on cooling rack and let cake cool completely in pan, about 2 hours.
Use icing spatula to spread frosting evenly over cooled cake (see photo, right). Cut cake into pieces and serve.
Milk Chocolate Frosting:Makes about 2 Cups
Prep Time: 5 Minutes
Cook time: 10 minutes, plus 1 hour chilling time
This recipe calls for just three ingredients but they are transformed by the microwave and refrigerator. Don’t use salted butter in this recipe. This recipe makes enough to frost 12 cupcakes or one sheet cake.
Prepare ingredients:11/3 cups milk chocolate chips
1/3 cup heavy cream
8 tablespoons unsalted butter, cut into 8 pieces and softened
Gather cooking equipment:Large microwave-safe bowl
Rubber spatula
Electric mixer
Start cooking:In large microwave-safe bowl, combine chocolate and cream. Heat microwave at 50 per cent power for 1 minute. Stop microwave and stir with rubber spatula. Heat in microwave at 50 per cent power until melted, 1 to 2 minutes. Remove bowl from microwave.
Add softened butter to chocolate mixture and use whisk to stir and break up large butter pieces. Let sit until butter is fully melted, about 5 minutes. Whisk until completely smooth.
Refrigerate frosting until cooled and thickened, about 1 hour.
Use electric mixer to beat frosting on medium-high speed until frosting is light and fluffy, 30 seconds.