Chocolate Walnut Cake
This easy, one layer snacking cake is moist and flavorful. It has toasted walnuts in the batter and sprinkled on top. It's spread with a velvety smooth whipped dark chocolate ganache.
Servings 1 8" square cake; 9-12 slices
Equipment
Ingredients
CHOCOLATE CAKE
- 66 grams walnuts
- 240 grams all purpose flour
- 1 teaspoon baking soda
- 1 teaspoon kosher salt Diamond Crystal
- 170 grams unsalted butter melted
- 45 mL vegetable oil neutral flavor
- 300 grams granulated sugar
- 30 grams cocoa powder Dutch process
- 240 mL coffee strongly brewed, hot
- 2 large eggs room temperature
- 120 grams sour cream full fat
- 7.5 mL vanilla extract
WHIPPED CHOCOLATE GANACHE TOPPING
- 180 mL heavy cream
- 170 grams dark chocolate finely chopped, I used a 60% chocolate bar
- 33 grams walnuts to sprinkle on top of cake
Instructions
CHOCOLATE CAKE
- Preheat oven to 350° F (177° C, Gas Mark 4).
- Line the bottom and sides of an 8 x 8 inch (20 cm) square pan with parchment paper.
- Toast all walnuts for both cake and topping. Chop walnuts into small pieces and place on a rimmed baking sheet. Bake at 350° F for 5-8 minutes, watching carefully to avoid browning them too darkly (they'll get bitter). Set aside to cool.
- In a medium bowl, sift together flour, baking soda and salt. Set aside.240 grams all purpose flour, 1 teaspoon baking soda, 1 teaspoon kosher salt
- In a large mixing bowl, whisk together melted butter, vegetable oil, sugar and cocoa powder. Mix well and add hot coffee (or water) and whisk to combine.170 grams unsalted butter, 45 mL vegetable oil, 300 grams granulated sugar, 30 grams cocoa powder, 240 mL coffee
- Add eggs one at a time, whisking well between additions to ensure they are fully incorporated.2 large eggs
- Add dry ingredients and whisk again. Scrape the bowl with a spatula to ensure no flour pockets remain. Add sour cream and vanilla, and whisk until completely blended and batter is smooth.120 grams sour cream, 7.5 mL vanilla extract
- Fold in ½ cup of the toasted, chopped walnut pieces. Pour batter into prepared pan. Rap pan firmly on countertop to remove air bubbles that may have formed in batter.66 grams walnuts
- Bake in center rack of oven for 45-50 minutes, until a toothpick inserted in the middle comes out clean, cake bounces back lightly when touched with a finger, and cake is beginning to pull away from the edges of the pan.
- Cool cake in pan for 10-15 minutes, then invert onto a cooling rack and remove parchment. Cool cake completely. Once cool, transfer to a serving platter.
WHIPPED CHOCOLATE GANACHE
- In a microwave safe container or small (1 quart) saucepan, heat cream until almost simmering. Remove from heat and add finely chopped dark chocolate. Let sit for 2-3 minutes, then whisk until all chocolate has melted and no lumps remain.180 mL heavy cream, 170 grams dark chocolate
- Let cool until room temperature. You can expedite the cooling process by placing the container in the refrigerator for two or three 10 minute intervals. Whisk every 10 minutes. You don't want it COLD. Just use the fridge to reach room temperature more quickly.
- Add cooled ganache to the bowl of a stand mixer fitted with the whisk attachment. Whisk for 1 minute on high, scraping down the bowl several times to make sure the chocolate is evenly whipped. Whipped ganache should be duller, much lighter in color, fluffy, and hold firm peaks when the whisk is lifted out. Do not overmix or it might become grainy.
- Using a small offset spatula, spread the whipped ganache in an even layer over the top of the cake. Leave the sides bare.
- Sprinkle the top of the cake with the remaining ¼ cup toasted walnuts.33 grams walnuts
Notes
Cake notes
- Toast your walnuts to bring out the richest flavor.
- If you don't drink coffee, feel free to replace it with hot water, black tea or milk.
- You can bake this cake in a 9 inch round pan without any changes to the recipe. Keep the baking time the same.
- Double this chocolate and walnut cake recipe using the 2x button in the recipe card. You'll use a 9 x 13 inch pan to bake the cake. Start checking the cake 5 minutes earlier, at the 40 minute mark.
- Whipped ganache should be duller, much lighter in color, fluffy, and hold firm peaks when the whisk is lifted out. Do not overmix or it might become grainy.
- Store this cake in an airtight container at room temperature for up to 2 days. After that, store any leftovers in the refrigerator covered with aluminum foil or plastic wrap.