Whisk together first 5 ingredients in a saucepan over medium-low heat; cook, whisking constantly, 13 to 15 minutes or until thickened. Remove from heat; stir in butter and vanilla until butter melts. Layer half of pound cake cubes, half of bananas, and half of pudding mixture in a 3-quart round baking dish. Repeat layers. Cover pudding, and chill 6 hours.
Spread Meringue over pudding.
Bake at 375° for 15 minutes or until golden brown.
Note: For testing purposes only, we used Sara Lee Family Size All Butter Pound Cake.