This Chocolate Walnut Cream Sheet Cake is a rich, soft chocolate cake baked in a convenient sheet pan, topped with a silky cream frosting and finished with crunchy toasted walnuts. It is easy enough for a family dessert but impressive enough for birthdays, holidays, potlucks, and gatherings.
The cake stays wonderfully moist, while the creamy topping balances the deep chocolate flavor and the walnuts add a satisfying crunch.
🍫 Recipe Overview
- Prep Time: 25 minutes
- Bake Time: 25–30 minutes
- Cooling Time: 30–45 minutes
- Total Time: About 1½ hours
- Servings: 15–20 squares
- Course: Dessert
- Difficulty: Easy to Moderate
Ingredients
For the Chocolate Cake
- 2 cups all-purpose flour
- 1¾ cups granulated sugar
- ¾ cup unsweetened cocoa powder
- 1½ teaspoons baking soda
- 1 teaspoon baking powder
- ½ teaspoon salt
- 2 large eggs
- 1 cup buttermilk
- ½ cup vegetable oil
- 2 teaspoons vanilla extract
- 1 cup hot brewed coffee or hot water
For the Walnut Topping
- 1 cup walnuts, roughly chopped
- 1 tablespoon unsalted butter
- 1 tablespoon brown sugar
- Pinch of salt
For the Cream Frosting
- 8 ounces cream cheese, softened
- ½ cup unsalted butter, softened
- 2½ cups powdered sugar
- 2 tablespoons heavy cream or milk
- 1½ teaspoons vanilla extract
- Pinch of salt
Optional Chocolate Drizzle
- ½ cup semisweet chocolate chips
- 2 tablespoons heavy cream
How to Make Chocolate Walnut Cream Sheet Cake
1. Prepare the Baking Pan
Preheat your oven to 350°F (175°C).
Grease a 9 × 13-inch sheet pan thoroughly.
For easier removal, line the bottom with parchment paper, leaving a little overhang along two sides.
2. Toast the Walnuts
Before making the cake, toast the walnuts.
Place the chopped walnuts in a dry skillet over medium-low heat.
Toast for approximately 4–6 minutes, stirring frequently.
When the walnuts become fragrant and lightly golden, remove them from the heat.
Add the butter, brown sugar, and salt while the nuts are still warm.
Stir until evenly coated.
Set aside to cool.
Watch the walnuts carefully because they can burn quickly.
3. Mix the Dry Ingredients
In a large bowl, whisk together:
- Flour
- Cocoa powder
- Sugar
- Baking soda
- Baking powder
- Salt
Break up any lumps of cocoa powder.
This ensures the chocolate flavor is evenly distributed throughout the cake.
4. Add the Wet Ingredients
Add the eggs, buttermilk, vegetable oil, and vanilla extract to the dry ingredients.
Mix with a whisk or electric mixer on low speed until the batter is smooth.
Don’t overmix.
5. Add the Hot Coffee
Slowly pour in the hot coffee while mixing gently.
The batter will become quite thin.
Don’t worry—this is exactly what you want.
Hot coffee intensifies the chocolate flavor without necessarily making the finished cake taste strongly of coffee.
If you prefer not to use coffee, simply substitute hot water.
6. Bake the Cake
Pour the batter into the prepared sheet pan.
Smooth the surface with a spatula.
Bake for approximately 25–30 minutes.
Begin checking around 25 minutes.
The cake is done when:
- The center springs back lightly when touched.
- A toothpick inserted into the center comes out with a few moist crumbs.
- The edges begin pulling slightly away from the pan.
Avoid overbaking because a sheet cake can dry out quickly.
7. Cool Completely
Remove the cake from the oven.
Place the pan on a wire rack and allow the cake to cool for approximately 30–45 minutes.
The cake should be completely cool before applying the cream frosting.
If the cake is warm, the frosting can become soft and slide across the surface.
Make the Cream Frosting
8. Beat the Butter and Cream Cheese
Place the softened cream cheese and butter in a large bowl.
Beat for approximately 2–3 minutes, until smooth and creamy.
Scrape down the sides of the bowl as needed.
9. Add the Powdered Sugar
Gradually add the powdered sugar.
Mix on low speed initially to prevent the sugar from flying everywhere.
Increase the speed and beat until smooth.
Add the vanilla extract and salt.
10. Adjust the Consistency
Add the heavy cream or milk, one tablespoon at a time.
Beat until the frosting is smooth, fluffy, and easy to spread.
If it seems too thin, add a little more powdered sugar.
If it seems too thick, add another teaspoon of cream or milk.
11. Frost the Cake
Once the cake has cooled completely, spread the cream frosting evenly over the top.
Use an offset spatula to create gentle swirls.
For a more decorative finish, pipe small rosettes or swirls around the edges.
12. Add the Toasted Walnuts
Sprinkle the toasted walnuts generously over the frosting.
Press them very gently into the frosting so they stay in place when the cake is sliced.
For an especially attractive finish, reserve a few larger walnut pieces for the center.
Optional Chocolate Drizzle
13. Make the Chocolate Drizzle
Place the chocolate chips and heavy cream in a small microwave-safe bowl.
Heat in 15–20 second intervals, stirring between each interval.
Continue until smooth.
Allow the chocolate to cool slightly.
Drizzle it lightly over the frosted cake.
Don’t use the chocolate while it’s extremely hot, or it may melt the cream frosting.
14. Chill Before Serving
Refrigerate the cake for approximately 30 minutes before slicing.
This allows the frosting to firm up slightly and makes cleaner slices.
Use a sharp knife and wipe it clean between cuts for neat, bakery-style squares.
Tips for the Best Chocolate Walnut Sheet Cake
Use good cocoa powder
Since chocolate is the main flavor, a good-quality unsweetened cocoa powder makes a noticeable difference.
Don’t overmix
Once the flour is incorporated, mix just until combined.
Hot coffee improves chocolate flavor
Coffee enhances the depth of chocolate without making the cake taste like coffee.
Toast the walnuts
Toasting brings out the walnuts’ natural oils and makes them more flavorful and crunchy.
Cool completely before frosting
This is one of the most important steps.
Don’t overbake
The cake should remain soft and moist in the center.
Delicious Variations
Chocolate Pecan Sheet Cake
Replace the walnuts with chopped pecans.
Toast them before adding them to the frosting.
Mocha Cream Cake
Add 1 teaspoon instant espresso powder to the hot coffee for a stronger mocha flavor.
Coconut Chocolate Cake
Add ½ cup toasted shredded coconut along with the walnuts.
Peanut Butter Cream Cake
Replace part of the cream cheese frosting with smooth peanut butter for a chocolate-peanut butter combination.
Cherry Chocolate Cake
Scatter chopped maraschino cherries or dried cherries over the frosting before adding the walnuts.
Dark Chocolate Version
Use dark cocoa powder and dark chocolate chips for a more intense chocolate flavor.
Make-Ahead Instructions
The cake can be baked one day ahead.
Allow it to cool completely, then cover tightly and keep at room temperature.
The frosting can also be prepared a day ahead and refrigerated.
Allow it to soften slightly at room temperature before spreading.
For the best texture, add the walnuts shortly before serving.
Storage
Because the frosting contains cream cheese, store the finished cake in the refrigerator.
Keep it covered and consume within approximately 3–4 days.
For the best flavor and texture, allow individual slices to sit at room temperature for about 15–20 minutes before serving.
Can You Freeze It?
Yes.
For best results, freeze the unfrosted cake.
Wrap the completely cooled cake tightly in plastic wrap and then aluminum foil.
Freeze for up to 2–3 months.
Thaw overnight in the refrigerator, then frost and decorate.
Individual frosted slices can also be frozen, although the frosting texture may change slightly after thawing.
Frequently Asked Questions
Can I use water instead of coffee?
Yes. Hot water works perfectly well. Coffee simply gives the chocolate flavor more depth.
Can I use a different pan?
Yes. A jelly-roll pan will produce a thinner cake and may require a shorter baking time. Always begin checking early.
Can I use milk instead of buttermilk?
Yes. For a quick substitute, add about 1 tablespoon lemon juice or white vinegar to 1 cup milk, let it stand for 5–10 minutes, then use the amount needed for the recipe.
Why is my cake dry?
The most common reason is overbaking. Start checking the cake around 25 minutes and remove it as soon as a toothpick comes out with a few moist crumbs.
Can I leave out the walnuts?
Absolutely. The cake will still be delicious without them. You can replace them with pecans, almonds, or toasted coconut.
Approximate Nutrition
Per serving, assuming 20 servings:
- Calories: 390
- Carbohydrates: 48 g
- Protein: 5 g
- Fat: 21 g
- Saturated Fat: 9 g
- Sugar: 33 g
- Fiber: 3 g
- Sodium: 250 mg
Nutrition values are estimates and vary according to ingredients and serving size.