Description
This Chocolate Mayonnaise Sheet Cake is a moist, rich chocolate cake made with mayonnaise for an incredibly tender crumb. Topped with a luscious cocoa and dark chocolate frosting, it's perfect for any celebration or simple indulgence.
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, combine the flour, cocoa powder, baking powder, baking soda, and salt until evenly mixed. Set aside.
- Dissolve coffee: In a glass measuring cup, dissolve the instant coffee powder in the hot water and set aside.
- Beat mayonnaise and sugars: In a large bowl, beat the mayonnaise with white and brown sugars using an electric mixer until pale and creamy.
- Add eggs and vanilla: Add eggs one at a time to the mayonnaise mixture, beating well after each addition. Scrape down the sides as needed. Then mix in vanilla extract.
- Combine wet and dry ingredients: Add the dry ingredients to the wet mixture in thirds, alternating with the dissolved coffee in halves. Beat after each addition until incorporated. The batter should be smooth but not too runny or stiff.
- Bake the cake: Pour the batter into the prepared pan and bake for 30 minutes or until a toothpick inserted in the center comes out with moist crumbs. Let the cake cool completely before frosting.
- Melt chocolate: In a microwave-safe bowl, melt the chopped chocolate in 20-second intervals, stirring between each until smooth. Let cool slightly.
- Beat butter and powdered sugar: Beat the butter in a large bowl until creamy. Gradually add powdered sugar at low speed, then increase to high and beat for 2 to 3 minutes until fluffy.
- Add cocoa powder: Mix the cocoa powder into the frosting, scraping the bowl sides to combine evenly.
- Incorporate cream and melted chocolate: Add the heavy cream and cooled melted chocolate to the frosting and beat until fully combined. Chill frosting for 10 minutes before use.
- Frost the cake: Spread the frosting evenly over the cooled cake and create swirls using a spatula or the back of a spoon.
- Serve and store: Slice and serve the cake. Keep the unfrosted cake covered at room temperature for 1 day or refrigerated up to 7 days. After frosting, store in the fridge for up to 3 days. Bring to room temperature before serving to soften the frosting.
Notes
- Use mayonnaise to add moisture and tenderness to the cake while keeping it rich.
- Make sure the melted chocolate for the frosting cools before mixing to prevent melting the butter.
- The coffee enhances the chocolate flavor but can be omitted if preferred.
- Store the cake well wrapped to prevent drying out.
- Bringing the frosted cake to room temperature before slicing makes serving easier as the frosting firms up in the fridge.
Nutrition
- Serving Size: 1 slice
- Calories: 350 kcal
- Sugar: 30 g
- Sodium: 210 mg
- Fat: 20 g
- Saturated Fat: 9 g
- Unsaturated Fat: 9 g
- Trans Fat: 0 g
- Carbohydrates: 40 g
- Fiber: 3 g
- Protein: 4 g
- Cholesterol: 45 mg
