Preheat your Z Grills pellet grill to 400 to 450 °F.
Make a long cut through the skin on the concave side of each banana, and pull the peel apart slightly.
Place the bananas in a grill basket, cut-side up. Grill, uncovered, until banana is warmed through and the peel is mostly black, about 10 minutes.
Remove bananas from the basket and set them aside. Add vanilla wafers to the basket, and grill until cookies get slightly charred, about 1 minute.
Divide ice cream evenly among 4 bowls. Peel bananas, and cut each diagonally into 5 pieces. Top the ice cream with bananas, whipped topping, caramel sauce, and chocolate sauce. Coarsely break up vanilla wafers, and sprinkle over bowls. Top with cherries.