Indulge in this rich chocolate walnut cake! This easy, one layer snacking cake is moist, packed with toasted nuts and topped with a velvety smooth whipped dark chocolate ganache.
Course Dessert, Snack
Cuisine American
Prep Time 45 minutesminutes
Cook Time 45 minutesminutes
Total Time 2 hourshours
Servings 18 inch (20 cm) square cake, approximately 9-12 slices
30grams (¼ cup + 2 Tablespoons) Dutch process cocoa powder
250mL (1 cup) coffee(strongly brewed, hot)
2largeeggs(room temperature)
120grams (½ cup) sour cream(full fat)
1½teaspoonsvanilla extract
98grams (¾ cup)walnuts, divided(for both cake and topping)
WHIPPED CHOCOLATE GANACHE TOPPING
188mL (¾ cup; 6 ounces)heavy cream
170grams (6 ounces)dark chocolate(finely chopped; I used a 60% chocolate bar)
Instructions
CHOCOLATE CAKE
Preheat oven to 350° F (177° C, Gas Mark 4).
Line the bottom and sides of an 8 inch (20 centimeter) square cake pan with parchment paper.
Toast all the walnuts: chop the walnuts into small pieces and place on a 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 (2 cups) 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 (¾ cup; 6 ounces) unsalted butter, 45 mL (3 Tablespoons) neutral vegetable oil, 300 grams (1½ cups) granulated sugar, 30 grams (¼ cup + 2 Tablespoons) Dutch process cocoa powder, 250 mL (1 cup) 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.
Fold in½ 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.
98 grams (¾ cup) walnuts, divided
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. 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.)
188 mL (¾ cup; 6 ounces) heavy cream, 170 grams (6 ounces) dark chocolate
Add the 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 an 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 walnuts.
Notes
Coffee - If you don't drink coffee, feel free to replace it with water, black tea or milk.Storage - 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.Double recipe - You can easily double this chocolate and walnut cake recipe using the 2x button in the recipe card. You'll use a 9 x 13 pan to bake the cake. Start checking the cake 5-10 minutes earlier. bl