- 1 tablespoon butter, softened
- 2 tablespoons cocoa powder
- 5 oz chopped bittersweet chocolate or chocolate chips
- 1 (19-ounce) can garbanzo beans, rinsed and drained
- 4 large eggs
- 1/2 teaspoon vanilla extract (optional)
- 1/2 cup granulated sugar
- 1/2 teaspoon baking powder
- 1/2 teaspoon salt
Adjust oven rack to middle position and preheat oven to 350°F. Grease interior of 1 pound loaf pan with flour, then dust all surfaces with cocoa, tapping out extra.
In a large microwave-safe bowl, melt chocolate by microwaving in 15-second intervals, stirring with a rubber spatula each time until melted. Alternatively, heat, stirring constantly, over double boiler until melted.
Puree beans, eggs and vanilla in a food processor (or using an immersion blender) until smooth, about 1 minute. Add sugar, baking powder and salt and blend to combine, about 20 seconds.
Add melted chocolate and blend to combine, scraping down sides of bowl well as necessary. Batter will have a thick, pudding-like consistency. Transfer batter into prepared pan and bake until knife inserted in center comes out clean, about 1 hour.
Allow cake to cool for 15 minutes on wire cooling rack before inverting onto serving platter. Cool completely. Dust with confectioner's sugar just before serving.