Ingredients

• Nonstick vegetable oil spray
• 1 cup all purpose flour
• 1 cup sugar
• 1/2 cup whole wheat pastry flour*
• 6 tablespoons unsweetened cocoa powder
• 1 teaspoon baking soda
• 1/2 teaspoon salt
• 3/4 cup water
• 1/3 cup vegetable oil
• 1/4 cup frozen orange juice concentrate, thawed
• 1 teaspoon vanilla extract
• 1 teaspoon distilled white vinegar
• 8 ounces bittersweet chocolate (donot exceed 61% cacao), chopped
• 6 tablespoons (3/4 stick) vegan "butter" (such as Earth Balance) or margarine, room temperature
• 1 cup powdered sugar
• 3 tablespoons frozen orange juice concentrate, thawed, divided
• 1/2 teaspoon vanilla extract
• Large pinch of salt
• 1/4 cup light agave nectar**

Instructions

1. Preheat oven to 350°F. Spray 9-inch diameter cake pan with 2-inch-high sides with nonstick spray. Sift all purpose flour, sugar, whole wheat flour, cocoa powder, baking soda, and salt into large bowl. Add 3/4 cup water, oil, juice concentrate, vanilla, and vinegar and whisk to blend. Transfer batter to prepared pan.
2. Bake cake until tester inserted into center comes out clean, about 35 minutes. Cool cake in pan on rack. Carefully cut around pan sides and turn out cake onto serving platter.
3. For frosting: Place chopped bittersweet chocolate in medium metal bowl. Set bowl over saucepan of barely simmering water. Stir constantly until chocolate is melted and smooth. Carefully transfer bowl to work surface. Cool melted chocolate to room temperature, stirring occasionally, 15 to 20 minutes. Using electric mixer, beat "butter" in large bowl until smooth. Add powdered sugar, 1 tablespoon juice concentrate, vanilla, and salt; beat until smooth. Add 2 tablespoons juice concentrate; beat until blended. Beat in agave nectar, then chocolate. Let stand 10 minutes. Frost top and sides of cake. DO AHEAD: Cake can be made up to 8 hours ahead. Cover with cake dome and store at room temperature.
4. Place chopped bittersweet chocolate in medium metal bowl. Set bowl over saucepan of barely simmering water. Stir constantly until chocolate is melted and smooth. Carefully transfer bowl to work surface. Cool melted chocolate to room temperature, stirring occasionally, 15 to 20 minutes.
5. Using electric mixer, beat "butter" in large bowl until smooth. Add powdered sugar, 1 tablespoon juice concentrate, vanilla, and salt; beat until smooth. Add 2 tablespoons juice concentrate; beat until blended. Beat in agave nectar, then chocolate. Let stand 10 minutes. Frost top and sides of cake. DO AHEAD: Cake can be made up to 8 hours ahead. Cover with cake dome and store at room temperature.
6. Also called whole grain pastry flour; available at some supermarkets and at most natural foods stores. ** A natural sweetener made from the sap of agave succulent plants; sold at some supermarkets and at natural foods stores.
7. Also called whole grain pastry flour; available at some supermarkets and at most natural foods stores.
8. ** A natural sweetener made from the sap of agave succulent plants; sold at some supermarkets and at natural foods stores.