Preheat oven to 350°.
To prepare cake, coat a 13 x 9-inch baking pan with cooking spray; line bottom of pan with wax paper. Coat wax paper with cooking spray; set aside.
Pour boiling water over 1/2 cup cocoa in a small bowl, stirring to dissolve cocoa; cool mixture.
Place 1 1/3 cups sugar and butter in a large bowl; beat with a mixer at medium speed 5 minutes or until well blended. Add cocoa mixture and egg substitute, beating well.
Lightly spoon flour into dry measuring cups; level with a knife. Combine flour, baking soda, and 1/4 teaspoon salt, stirring with a whisk. Add flour mixture and sour cream alternately to sugar mixture, beginning and ending with flour mixture; mix after each addition. Beat in vanilla. Pour batter into prepared pan. Sharply tap pan once on counter to remove air bubbles. Bake at 350° for 30 minutes or until a wooden pick inserted in center comes out clean. Cool in pan 10 minutes on a wire rack; remove from pan. Carefully peel off wax paper; cool completely on wire rack. Spread jam over top of cake.
To prepare ganache, combine 1/2 cup sugar, milk, and 1/4 cup cocoa in a medium saucepan over medium heat; bring to a boil, stirring frequently. Cook 1 minute, stirring constantly. Remove from heat; add 1/2 teaspoon vanilla extract, 1/8 teaspoon salt, and chopped chocolate, stirring until smooth. Spread ganache evenly over top of cake, allowing ganache to run down the sides. Let cake stand for 20 minutes or until set. Garnish with raspberries and mint leaves, if desired.