Preheat half of a grill to low heat and the other half to medium heat. Arrange the bacon on the grate over low heat, cover and cook, turning halfway through, until crisp, about 10 minutes. Drain on paper towels, then crumble.
Brush the hot grate with oil and arrange the bananas cut side down on the grate over medium heat. Cover and grill until grill marks appear, 1 to 2 minutes. Flip, cover and grill for 1 minute more.
Divide the warm banana pieces among 6 bowls. Add scoops of the ice cream, drizzle with the honey and top with the crumbled bacon and the butter toffee.