Sure, you can make a cake from a box, but once you know how easy and delicious the real deal is, it’ll be hard to turn back. Instead of creaming butter and sugar together, this cake uses a mixture of vegetable oil and melted butter, which means it comes together quickly. Not to mention, the crumb is rich and dense with classic yellow cake flavor. And, it wouldn't be a classic birthday cake without fudgy frosting. This one uses both semisweet and milk chocolate to create a rich ganache-style frosting. Spread over the cooled cake in generous swoops using an offset spatula.
How to Make It
Make the Cake: Preheat oven to 350°F. Lightly butter a 9-by-13-inch baking pan and dust with flour, tapping out excess.
Whisk together flour, baking powder, salt, and baking soda in a medium bowl; set aside.
Using an electric mixer fitted with the whisk attachment, beat eggs and sugar on medium-high until pale and thick, about 4 minutes. With mixer running, add melted butter and oil and beat until evenly combined. Beat in vanilla extract.
With mixer on low, add flour mixture in 3 additions and milk in 2 additions, beginning and ending with flour mixture. Mix just until combined (do not overmix).
Transfer batter to prepared baking pan and bake until a toothpick inserted in center comes out clean, 35 to 40 minutes. Let cool completely.
Make the Frosting: Place both types of chocolate chips in a large bowl. Heat cream and salt in a medium saucepan over high. As soon as mixture begins to boil, pour over chocolate and let stand for 3 minutes. Add vanilla extract and whisk until melted and smooth. Let cool to room temperature, stirring occasionally.
Using an electric mixer, beat ganache until fluffy and a shade lighter, about 4 minutes. Spread evenly over cake.