Banana chocolate marble cake

---------- Recipe via Meal-Master (tm) v8.05
  
       Title: Banana Chocolate Marble Cake
  Categories: Cheesecakes, Chocolate
       Yield: 8 servings
  
   2 1/4 c  All-purpose flour
       1 ts Baking soda
   1 1/4 c  Light brown sugar
     1/4 c  Salted butter
     1/2 c  Sour cream
   1 1/2 c  Mashed bananas
       1 lg Egg
       1 ts Pure vanilla extract
       6 oz Semisweet chocolate chips
            Melted
       1 tb Orange zest
            Ganache:
     1/2 c  Heavy cream
       6 oz Semisweet chocolate chips
       1 ts Orange zest
  
     Cake: Preheat oven to 350 degrees.  Grease a square
   baking pan. Combine flour and baking soda and mix well and
   set aside.  Blend sugar and butter using electric mixer and
   scrape sides of bowl when necessary.  Add sour cream,
   banana, egg and vanilla and beat until smooth.  Add flour
   mixture and blend just until combined on low speed. Gently
   fold in melted chocolate and zest and stir just until
   marbled pattern develops.  Do not overmix.  Pour batter
   into baking pan. Bake 40-45 minutes or until toothpick
   inserted into center comes out clean.  Cool in pan 15
   minutes and invert onto rack.  Cool to room temperature.
     Ganache: scald cream in saucepan and remove from heat.
   Add chocolate and zest.  Stir until blended and cover pan.
   Set aside.  After about 15 minutes, stir frosting until it
   is smooth and pour into a bowl. Chill until firm.  Flip
   cake right side up onto a serving plate and frost with
   ganache.
  
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