Description
This Chocolate Mayonnaise Sheet Cake is a moist and rich chocolate cake made with mayonnaise for added tenderness and great texture. Topped with a luscious chocolate frosting, it's a delicious treat perfect for any occasion.
Ingredients
Scale
For the Cake
- Butter, for greasing the pan
- 2 cups (242g) all-purpose flour
- 1 cup (120g) unsweetened Dutch processed cocoa powder
- 1 1/2 teaspoons baking powder
- 1 1/2 teaspoons baking soda
- 1/4 teaspoon salt
- 3/4 cup (177ml) hot water
- 2 tablespoons (30g) instant coffee powder or instant espresso powder
- 2 large eggs
- 1 cup (220g) sugar
- 1/2 cup (100g) brown sugar, lightly packed
- 1 cup (260g) mayonnaise
- 1 tablespoon vanilla extract
For the Frosting
- 1/2 cup (80g) finely chopped semisweet or bittersweet chocolate
- 1/2 cup (113g) unsalted butter
- 2 tablespoons (30g) unsweetened Dutch processed cocoa powder
- 1 cup (130g) powdered sugar
- 1/2 cup heavy cream
Instructions
- Preheat and prepare pan: Preheat the oven to 350°F (180°C). Brush a 9x13-inch sheet pan with butter and set aside.
- Mix dry ingredients: In a medium bowl, stir together the all-purpose flour, cocoa powder, baking powder, baking soda, and salt until evenly combined. Set aside.
- Dissolve coffee: In a glass measuring cup, add the instant coffee powder to the hot water, stirring until dissolved. Set aside.
- Cream mayonnaise and sugars: In a large mixing bowl, beat the mayonnaise, white sugar, and brown sugar with an electric mixer until pale and creamy.
- Add eggs and vanilla: Add eggs one at a time, beating well after each addition. Scrape the sides of the bowl with a spatula periodically to ensure even mixing. Pour in the vanilla extract and beat to combine.
- Combine wet and dry ingredients: Divide the dry ingredients into thirds. Add the first third of dry ingredients with half of the hot coffee mixture to the wet ingredients and beat until combined. Add the second third of dry ingredients with the remaining coffee and beat well. Add the final third and mix until the batter is smooth and neither stiff nor runny.
- Bake the cake: Pour the batter into the prepared pan and bake at 350°F (180°C) for 30 minutes or until a toothpick inserted in the center comes out with moist crumbs. Let the cake cool completely before frosting.
- Melt the chocolate for frosting: In a microwave-safe bowl, melt the chopped chocolate in 20-second intervals, stirring between each, until smooth and fully melted. Let cool.
- Beat butter and sugar: In a large bowl, beat the butter until creamy and fluffy. Gradually add powdered sugar starting on low speed, increase speed, and beat for 2 to 3 minutes until light and smooth.
- Add cocoa powder: Add cocoa powder to the frosting and beat until fully combined, scraping the bowl sides as needed.
- Add cream and melted chocolate: Mix the heavy cream and cooled melted chocolate into the frosting until smooth. Chill frosting in the fridge for 10 minutes before frosting the cake.
- Frost the cake: Spread the frosting evenly over the cooled cake and create swirls with a spatula or spoon.
- Serve and store: Slice and serve. Store unfrosted cake at room temperature covered for 1 day or in the refrigerator for up to 7 days. Store frosted cake in the fridge for 3 days; bring to room temperature before serving.
Notes
- Use Dutch processed cocoa powder for a smoother, less acidic chocolate flavor.
- Instant coffee in the batter enhances the chocolate taste but can be omitted if desired.
- Ensure the melted chocolate for the frosting has cooled before adding to prevent melting the butter.
- Do not overbake; the toothpick should come out with moist crumbs, not wet batter.
- Room temperature ingredients help better incorporation and texture.
- Allow frosted cake to come to room temperature for easier slicing as the frosting firms when chilled.
Nutrition
- Serving Size: 1 slice (approx. 1/12 of cake)
- Calories: 360 kcal
- Sugar: 35 g
- Sodium: 250 mg
- Fat: 20 g
- Saturated Fat: 9 g
- Unsaturated Fat: 9 g
- Trans Fat: 0 g
- Carbohydrates: 42 g
- Fiber: 3 g
- Protein: 4 g
- Cholesterol: 55 mg
