I share a lot of layer cake recipes here. It’s my thing. If you’ve visited this site before, you’ve probably seen my chocolate espresso layer cake or my cardamom vanilla bean layer cake. I find them relaxing to prepare and beautiful to gaze upon. But there are many steps involved, and I use a lot of specialty equipment. The truth is that layer cakes aren’t always the most practical option for parties. Sheet cakes, on the other hand, are perfect. One big layer, no fancy decorating tools, and you easily get over 20 squares of cake.
There is no better cause for celebration than new life. My good friend Joanne, who writes the delectable blog Fifteen Spatulas, and her husband, Pete, have welcomed a heathy, beautiful baby boy named James. I am so incredibly happy for them! I feel very lucky to count Joanne as a close friend and confidant. She’s kind, funny, and has so many traits that I know will make her an incredible mother. James is a very lucky boy. He’s pretty cute, too.
While sheet cakes are generally much easier to prepare than layer cakes, I have a few suggestions if this is your first time baking one. You want to take some care when removing the cake from the pan after it has cooled.
Once the cake has cooled, gently run a pairing knife or offset spatula (my preference) along the edges to detach any portion of the cake that might have attached to the side of the sheet pan. Next, place a clean dishtowel on top of the cake, and top that with another sheet pan or a large cutting board. Pick up the pan and gently flip it over so that the cake inverts onto the dish towel.
Peel away the parchment paper. You can now place the cake on a large serving platter, cutting board, or even back into the same sheet pan if that’s how you’d like to serve it. But definitely remove that parchment paper so no one takes a bite out of it!
This frosting recipe is very forgiving. If it seems too thick, whisk in a bit more sour cream. If it’s too thin, sift/whisk in a bit more sugar, or (if you don’t want to increase the sweetness), place it in the refrigerator, whisking every 5 minutes, for 10-15 minutes to give the butter a chance to firm up slightly.
The best way to get clean slices with a cake is to use a long, thin knife. Cut straight down (do not use a sawing motion). Pull the knife straight out toward you. Wipe it off with a wet towel. Repeat. Or… make a big mess. Because cake.
60 minPrep Time
30 minCook Time
1 hr, 30 Total Time
- baking spray with flour
- 15 ounces (3 cups) all-purpose flour
- 1 1/2 teaspoons baking powder
- 1 teaspoon baking soda
- 1 teaspoon kosher salt
- 1 cup buttermilk
- 1/3 cup vegetable oil (see notes)
- 1 1/2 teaspoons pure vanilla extract
- 6 ounces (12 tablespoons) unsalted butter, room temperature
- 1 1/2 cups granulated sugar
- 1/3 cup packed light brown sugar
- 4 large egg yolks
- 2 large eggs
- 4 ounces (8 tablespoons) unsalted butter
- 2 ounces unsweetened chocolate, chopped
- 1/3 cup unsweetened cocoa powder, sifted
- 2 teaspoons pure vanilla extract
- 10 ounces (2 cups) confectioners' sugar, sifted
- 2/3 - 1 cup sour cream
- Preheat the oven to 350 degrees F. Lightly coat an 18x13 inch half-sheet pan with baking spray (the kind with flour incorporated works best), top with parchment paper, and coat with additional baking spray.
- In a medium-sized bowl, whisk together the flour, baking powder, baking soda, and kosher salt. Set aside. In a large liquid measuring cup, combine the buttermilk, vegetable oil and vanilla extract.
- In a stand mixer fitted with the paddle attachment, combine the butter, granulated sugar, and brown sugar on low speed and then slowly turn the mixer up to high speed and cream for 3-4 minutes until light and fluffy. Scrape down the sides. Turn down the speed to medium and add the eggs and yolks, one at a time, allowing each to fully incorporate, over the course of 4-5 minutes. Scrape down the sides all the way to the bottom. Turn the mixer speed down to low and alternate between adding the dry and wet ingredients, starting and ending with the dry.
- Scrape the batter into the prepared sheet pan, using a spatula (preferably an offset spatula) to even out the top of the cake. Make sure the batter is spread evenly into the 4 corners of the pan. Bake for 20-25 minutes, rotating the pan once halfway through, until the top is golden and springy, and a toothpick comes out clean from the center. Remove from the oven and allow to cool completely. The cake can be prepared 24 hours in advance (or longer, if frozen).
- In a saucepan set over low heat, melt the butter and chocolate together until smooth, stirring constantly. Once combined, pour into a large bowl and whisk in the cocoa powder and vanilla extract. Whisk in half of the sugar and sour cream (the frosting will be very thick). Keep adding the sugar and sour cream until the desired texture and flavor is reached. If the frosting seems too thin at any time, additional sugar can be sifted in. Or, to keep the sweetness level the same, place the frosting in the refrigerator and chill for 10-15 minutes, stirring every 5 minutes. This will allow the butter to firm up.
- Gently run a pairing knife or offset spatula along the edges of the pan to detach any portion of the cake that might have attached itself. Next, place a clean dishtowel on top of the cake, and top that with another sheet pan or a large cutting board. Pick up the pan and gently flip it over so that the cake inverts onto the dish towel.
- Peel away the parchment paper, and then gently flip the cake on a large serving platter, cutting board, or back into the same sheet pan (place the board or pan directly against the cake before inverting).
- Frost the cake evenly and cut into squares. Serve.
The original Bon Appetit sheet cake recipe calls for 1/3 cup vegetable oil, but I used avocado oil instead for health reasons (not that this is a healthy cake). Avocado oil has a neutral flavor which works well in this cake; you can use either. I did not include avocado oil in the main ingredient list because I realize it's an expensive ingredient that most people do not keep on hand.
Sheet cake recipe adapted from Bon Appetit . Chocolate Sour Cream Frosting Adapted from Epicurious .
Check out all of these other fabulous recipes that were prepared for the baby shower! Congratulations, Joanne! I can’t wait to meet him :)
Italian Sub Sandwich Roll-ups from Michael of Inspired by Charm
Smoky Roasted Red Pepper Sun Dried Tomato Hummus from Jeanette of Jeanette’s Healthy Living
Creamy Sweet Potato Soup from Sadie of Dairy Good Life
Whipped Goat Cheese & Blueberry Balsamic Crostini from Meseidy of The Noshery
Rosemary Flatbread with Baked Goat Cheese from Heidi of FoodieCrush
Spring Herb Cream Cheese Appetizer Cups from Rachel of Rachel Cooks
Crostini with Almond Ricotta and spicy olive tapenade from Heather of HeatherChristo
Chocolate-Covered Rice Krispies Treats from Julie of The Little Kitchen
Orange Fluff from Jamie of My Baking Addiction
Chocolate Peanut Butter Pretzel Brownies from Susannah of Feast + West
Mini Ombre Heart Cookies from Bridget of Bake at 350
Mini Coconut Pound Cakes from Mary of Barefeet In The Kitchen
Unicorn Shaped Cookies from Jessie of CakeSpy
Oreo Cheesecake Bites from Brenda of a farmgirl’s dabbles
Lemon Blueberry Bread from Glory of Glorious Treats
Blintz with Blackberry Sauce from Sommer of A Spicy Perspective
Pastel Rainbow Cake from Bree of Baked Bree
Individual Chocolate Souffles from Andie of Andie Mitchell