1. Combine chocolate syrup and peanut butter in a 1-cup glass measure. Microwave at HIGH 40 seconds or until peanut butter melts. Stir until smooth.
2. Cut each banana half crosswise into 2 pieces. Arrange 2 banana pieces in each of 6 dessert dishes; top banana with ice cream and hot chocolate sauce. Sprinkle with peanuts. Serve immediately.