Easy Chocolate Traybake: The Ultimate One-Pan Chocolate Cake Recipe
Easy Chocolate Traybake: The Ultimate One-Pan Chocolate Cake Recipe

This easy chocolate traybake recipe is the perfect solution when you need a quick, crowd-pleasing dessert that’s simple to make and even easier to serve. Whether you’re preparing for a bake sale, party, or just want a delicious everyday treat, this one-pan chocolate cake delivers moist, fudgy perfection every time.
What makes this recipe special is its versatility – it’s perfect for packed lunches, school cake-style desserts, or as a party slice cake that feeds a crowd. The simple sponge bakes evenly in a single pan, and the rich chocolate icing takes just minutes to prepare.

Ingredients
For the Cake:
- 2 cups all-purpose flour
- 1 3/4 cups granulated sugar
- 3/4 cup cocoa powder
- 2 teaspoons baking powder
- 1 teaspoon baking soda
- 1/2 teaspoon salt
- 2 large eggs
- 1 cup milk
- 1/2 cup vegetable oil
- 2 teaspoons vanilla extract
- 1 cup boiling water
For the Fudgy Icing:
- 1/2 cup butter
- 1/4 cup cocoa powder
- 1/4 cup milk
- 3 cups powdered sugar
- 1 teaspoon vanilla extract
Step-by-Step Instructions
Preheat your oven to 350°F (175°C). Grease and line a 9×13 inch baking pan with parchment paper.
Step 1: In a large mixing bowl, whisk together the flour, sugar, cocoa powder, baking powder, baking soda, and salt until well combined.
Step 2: Add the eggs, milk, vegetable oil, and vanilla extract to the dry ingredients. Mix on medium speed for 2 minutes until smooth and creamy.
Step 3: Carefully pour in the boiling water and mix until the batter is thin and smooth. Don’t worry – the thin consistency is perfect for a moist cake!
Step 4: Pour the batter into your prepared pan and bake for 30-35 minutes, or until a toothpick inserted in the center comes out clean.
Step 5: While the cake cools, prepare the fudgy icing. Melt the butter in a saucepan over medium heat, then whisk in the cocoa powder and milk until smooth.
Step 6: Remove from heat and gradually whisk in the powdered sugar and vanilla until you have a smooth, pourable icing consistency.
Step 7: Pour the warm icing over the completely cooled cake, spreading evenly with a spatula. Let the icing set before slicing into squares.
Expert Tips
For the Perfect Texture: Don’t skip the boiling water – it helps bloom the cocoa powder for maximum chocolate flavor and creates an incredibly moist crumb. This technique ensures your chocolate cake achieves bakery-style perfection with minimal effort.
Cutting Clean Slices: Use a hot, wet knife to slice the cake cleanly. Dip your knife in hot water, wipe it dry, then cut. This prevents the icing from sticking and gives you professional-looking slices perfect for party food setups.
Storage Tips: This cake keeps well at room temperature for up to 3 days in an airtight container. For longer storage, freeze individual slices wrapped in plastic wrap – they’ll be ready for packed lunches anytime!
FAQ Section
Can I make this cake gluten-free? Yes! Simply substitute the all-purpose flour with your favorite gluten-free flour blend. The texture may be slightly different, but it will still be delicious.
How can I make this cake dairy-free? Use plant-based milk and dairy-free butter alternatives. The recipe is very adaptable and works well with various substitutions.
Why is this called a “traybake”? Traybakes are single-layer cakes baked in rectangular pans and cut into squares or bars. They’re perfect for easy sheet cakes that feed crowds without the fuss of layered cakes.
Can I add mix-ins to this recipe? Absolutely! Chocolate chips, chopped nuts, or even a sprinkle of sea salt on the icing can elevate this simple dessert. Try it alongside other retro dessert favorites for a varied dessert table.
This easy chocolate traybake is truly the workhorse of dessert recipes – simple enough for beginners but impressive enough for any occasion. Its crowd-feeding capabilities make it ideal for everything from school bake sales to family gatherings.

Easy Chocolate Traybake: The Ultimate One-Pan Chocolate Cake Recipe
Ingredients
Method
- Preheat oven to 350°F (175°C). Grease and line a 9×13 inch baking pan with parchment paper
- In a large mixing bowl, whisk together flour, sugar, cocoa powder, baking powder, baking soda, and salt until well combined
- Add eggs, milk, vegetable oil, and vanilla extract to dry ingredients. Mix on medium speed for 2 minutes until smooth and creamy
- Carefully pour in boiling water and mix until batter is thin and smooth
- Pour batter into prepared pan and bake for 30-35 minutes, or until toothpick inserted in center comes out clean
- While cake cools, prepare fudgy icing by melting butter in saucepan over medium heat, then whisk in cocoa powder and milk until smooth
- Remove from heat and gradually whisk in powdered sugar and vanilla until smooth, pourable icing consistency
- Pour warm icing over completely cooled cake, spreading evenly with spatula. Let icing set before slicing into squares
