Heat oven to 350°F. Generously grease and flour 12-cup Bundt® pan. In large bowl, combine all cake ingredients; beat at low speed until moistened. Beat 2 minutes at high speed. Pour batter into greased and floured pan.
Bake at 350°F. for 40 to 50 minutes or until toothpick inserted in center comes out clean. Cool 15 minutes; remove from pan. Cool completely.
Meanwhile, in medium saucepan, combine eggnog, milk and regular pudding mix; with wire whisk, mix until smooth. Cook over medium heat until mixture comes to a boil, stirring constantly. Remove from heat; stir in 1/4 cup sherry. Place plastic wrap directly on surface of pudding; refrigerate 1 1/2 hours or until cool.
Place cake on serving plate. Sift powdered sugar over top of cake. Fill center with raspberries; garnish with mint leaves.
To serve, cut cake into thin slices; place on individual serving plates. Spoon sauce over cake; top with raspberries. Refrigerate any leftover custard sauce.