HEAT oven to 350°F.
SPRAY 12-cup fluted tube pan or 10-inch tube pan with cooking spray; dust with flour. Prepare cake batter as directed on package, reducing water to 1/2 cup and increasing oil to 1/2 cup. Add half the cream cheese, pumpkin, cinnamon and ginger; beat until blended. Stir in chocolate. Pour into prepared pan.
BAKE 40 to 45 min. or until toothpick inserted near center comes out clean. Cool 10 min. Remove from pan; cool completely on wire rack.
MIX remaining cream cheese, COOL WHIP and sugar until blended; spread onto cake.