The Ultimate Chocolate Sheet Cake with Milk Chocolate Frosting
If you’ve been searching for a chocolate cake that’s perfectly moist, rich, and irresistibly decadent — this Chocolate Sheet Cake with Milk Chocolate Frosting is the one to make. Every bite delivers deep chocolate flavor balanced with a silky, buttery frosting that melts beautifully into the tender crumb. It’s simple enough for everyday baking yet impressive enough for celebrations.
Why You’ll Love This Cake
- Deep chocolate flavor: Thanks to bittersweet chocolate and Dutch-processed cocoa.
- Unbelievably moist: A combination of milk and oil keeps the cake soft for days.
- Easy frosting: A simple milk chocolate and cream ganache that spreads like a dream.
- Crowd-friendly: Baked in a 9×13-inch pan — perfect for family gatherings or potlucks.
Ingredients
For the Cake:
- 1 ½ cups (10 ½ oz) granulated sugar
- 1 ¼ cups (6 ¼ oz) all-purpose flour
- ½ teaspoon baking soda
- ½ teaspoon salt
- 1 cup whole milk
- 8 oz bittersweet chocolate, finely chopped
- ¾ cup (2 ¼ oz) Dutch-processed cocoa powder
- ⅔ cup vegetable oil
- 4 large eggs
- 1 teaspoon vanilla extract
For the Frosting:
- 1 pound milk chocolate, chopped
- ⅔ cup heavy cream
- 16 tablespoons (2 sticks) unsalted butter, softened and cut into pieces
Instructions
Step 1: Prepare the Pan
Adjust your oven rack to the middle position and preheat the oven to 325°F (165°C). Lightly grease a 9×13-inch baking pan with vegetable oil spray and line the bottom with parchment paper for easy removal.
Step 2: Combine Dry Ingredients
In a medium mixing bowl, whisk together the sugar, flour, baking soda, and salt. Set aside.
Step 3: Melt the Chocolate Base
In a large saucepan, combine milk, chopped bittersweet chocolate, and cocoa powder. Place the pan over low heat, whisking frequently until the chocolate has completely melted and the mixture is smooth and glossy.
Step 4: Add Wet Ingredients
Remove the pan from heat and allow it to cool slightly for about 5 minutes. Whisk in the vegetable oil, eggs, and vanilla extract until the mixture is silky and well combined.
Step 5: Combine Batter
Add the dry ingredients to the chocolate mixture and whisk until smooth, scraping the corners of the saucepan to ensure everything is fully incorporated.
Step 6: Bake the Cake
Pour the batter into the prepared pan and smooth the top with a spatula. Bake for 30 to 35 minutes, rotating the pan halfway through, until the center is set and a toothpick inserted comes out with just a few moist crumbs attached.
Let the cake cool completely in the pan on a wire rack for 1 to 2 hours before frosting.
For the Frosting
Step 1: Melt the Chocolate
While the cake bakes, place chopped milk chocolate and heavy cream in a heatproof bowl set over a saucepan of simmering water (double boiler method). Ensure the bottom of the bowl doesn’t touch the water. Stir occasionally until smooth and glossy, about 10 to 15 minutes.
Step 2: Add the Butter
Remove from heat and whisk in the softened butter. Let the mixture stand for 5 minutes, then whisk again until the frosting is silky and completely smooth.
Step 3: Chill and Whip
Refrigerate the frosting for 30 minutes to 1 hour, until thickened but spreadable. Whisk briefly before using to restore its creamy texture.
Step 4: Frost the Cake
Once the cake is completely cooled, spread the frosting evenly over the top, pushing it gently to the edges. For a clean look, use an offset spatula to smooth the surface.
Cut the cake into squares and serve straight from the pan — perfect for sharing!
Tips for Success
- Use quality chocolate: The better the chocolate, the richer the flavor.
- Don’t overbake: The cake should spring back slightly when touched.
- For a deeper chocolate flavor: Replace 2 tablespoons of milk with brewed coffee or espresso.
- Storage: Store covered at room temperature for up to 2 days, or refrigerate for up to 5 days. Bring to room temperature before serving.
Serving Ideas
This chocolate sheet cake pairs wonderfully with a scoop of vanilla ice cream or a drizzle of chocolate sauce. It’s also a great make-ahead dessert for birthdays, holidays, and potlucks — moist, flavorful, and always a crowd favorite.