In a saucepan over medium heat on the stove, bring the cream, corn syrup, sugar, and cocoa powder to a boil, whisking constantly. Remove from the heat and add the chopped chocolate and butter. Whisk until smooth. Remove from the heat and allow to cool and thicken.
Using a handheld electric mixer on medium speed, beat the cream until the trail from the beaters is just visible, about 2 minutes. Add the confectioners' sugar and continue to beat until soft peaks form. Cover and refrigerate until ready to use.
Prepare the grill for direct cooking over medium heat (180° to 230°C).
Prepare the grill for cooking over medium heat (200°C).
Cut each banana lengthwise in half (do not peel), and then brush the cut side with the melted butter. Grill the bananas, cut side down, over direct medium heat, with the lid closed, until warm and nicely marked, 2 to 3 minutes (do not turn). Remove from the grill, cool slightly, and gently peel the bananas.
Cut each banana lengthwise in half (do not peel), and then brush the cut side with the melted butter. Grill the bananas, cut side down, over medium heat, with the lid closed, until warm and nicely marked, 2 to 3 minutes (do not turn). Remove from the grill, cool slightly, and gently peel the bananas.
If necessary, rewarm the sauce in a microwave oven on high power in 15-second increments until warm, but not hot. Place two banana halves (you may need to cut them in half to fit your bowl) in each of six bowls or sundae dishes. Add scoops of ice cream, the warm sauce, whipped cream, and a cherry. Serve immediately.
