1. Prepare COCOA STREUSEL. Heat oven to 350°F. Generously grease 12-cup fluted tube pan.
2. Beat butter and sugar in large bowl until well blended. Add eggs and vanilla; beat well. Add sour cream; beat until blended. Stir together flour, baking powder and baking soda; add alternately with orange juice to butter mixture, beating until well blended. Stir in orange peel.
3. Spread marmalade in bottom of prepared pan; sprinkle half of streusel over marmalade. Pour half of batter into pan, spreading evenly. Sprinkle remaining streusel over batter; spread remaining batter evenly over streusel.
4. Bake 1 hour to 1 hour and 5 minutes or until wooden pick inserted in center of cake comes out clean. With metal spatula, loosen cake from side of pan; immediately invert onto serving plate. Serve warm or cool. 12 servings.
COCOA STREUSEL: Stir together 2/3 cup packed light brown sugar, 1/2 cup chopped walnuts, 1/4 cup HERSHEY'S Cocoa and 1/2 cup MOUNDS Sweetened Coconut Flakes, if desired, in small bowl.