This fluffy, chocolaty cake is a blank canvas for your favorite frosting and decorations.
Adjust oven rack to middle position and heat oven to 325 degrees. Spray inside bottom and sides of each 9-inch round cake pan with vegetable oil spray. Line each cake pan with 9-inch round piece of parchment paper.
In medium bowl, whisk together flour, sugar, cocoa, baking powder, baking soda, and salt.
In large bowl, whisk together milk, oil, eggs, and vanilla.
Add flour mixture to liquid mixture and use rubber spatula to stir until just combined and no dry flour is visible. Do not overmix.
Use rubber spatula to divide batter evenly between parchment-lined cake pans and smooth tops. (Spread batter out to edges of each pan to create even layer.)
Place cake pans in oven. Bake until toothpick inserted in center of each cake comes out clean, 34 to 36 minutes.
Use oven mitts to remove cake pans from oven (ask an adult for help). Place cake pans on cooling rack and let cakes cool completely in pans, about 1 hour.
Run butter knife around edge of each cake to loosen cake from pan (see photos, below). Remove cakes from their pans and discard parchment paper. Assemble and frost cake (click here to learn how to frost a layer cake). Cut cake into wedges and serve.
Lining cake pans with parchment paper rounds prevents cakes from sticking and makes them easier to remove. Cardboard rounds help with moving frosted cakes from one place to another. Here’s how to cut parchment rounds:
A process called Dutching, which was invented in the 19th century by a Dutch chemist and chocolatier named Coenraad Van Houten, gives cocoa powder a more chocolaty flavor and deeper brown color. Dutching also raises cocoa powder’s pH level (pH tells us how acidic or basic something is). Dutch-processed cocoa powder, sometimes called alkalized or European-style cocoa powder, is the best choice for most baked goods, including this chocolate cake. Using a natural (unalkalized) cocoa powder creates a drier cake that is a lighter brown color.