mix milk & pudding mix w/ electric mixer on medium for 2 minutes. Layer 20 vanilla wafers in bottom of casserole dish or pie plate. Slice one banana & arrange on top of vanilla wafers. Pour half of pudding over wafers & bananas. Layer 20 vanilla wafers, then slice the second banana & arrange on top of wafers & pudding. Pour remaining pudding over wafers & banana. Chill 1 hour.