Cook the peanut butter, chocolate chips, Karo syrup, and water in a pot over medium heat, stirring, until chocolate is melted. Remove from heat and mix in the rice crispies and chopped peanuts.

Pour peanut chew mixture onto a baking sheet and smooth top. Allow to harden.

Cut peanut chews into ½x3-inch (1¼X7½-cm) bars.

This step needs to be done in advance. Put a little melted chocolate on a plate and use a pastry comb to make a design. Sprinkle chopped nuts on chocolate. Allow to dry. For easy storage, pile them up with a piece of plastic wrap in between each plate.

Place bars and martini glass filled with ice cream on each plate.