Combine first 3 ingredients in a large saucepan. Whisk in milk, half-and-half, and egg yolks. Cook over medium heat, whisking constantly, until smooth and thickened. Remove from heat, and stir in chocolate morsels and 1 tablespoon vanilla.
Reserve 14 wafers; arrange one-third of remaining chocolate wafers in the bottom of a 4-quart baking dish. Slice 2 bananas, and layer over wafers. Top with one-third of pudding mixture. Repeat layers twice; arrange reserved wafers around edge of dish.
Beat egg whites at high speed with an electric mixer until soft peaks form. Gradually add 1/3 cup sugar, 1 tablespoon at a time, beating until stiff peaks form. Fold in 1/2 teaspoon vanilla. Spread meringue over pudding, sealing to edge of dish.
Bake at 325° for 25 minutes or until golden.