Preparation Preheat oven to 350°F. Toss pecans, maple syrup, and salt on a parchment paper-lined rimmed baking sheet; spread out in a single layer. Bake until maple syrup is caramelized and pecans are toasted, 10-15 minutes. Let cool completely on baking sheet. Coarsely chop nuts; set aside. Meanwhile, bring whiskey, both sugars, and butter to a boil in a large skillet (do not move pan or mixture may ignite). Turn off heat; stir mixture to dissolve sugar completely. Return to medium heat and simmer until sauce is thickened and glossy, about 2 minutes. Add bananas and cook, swirling skillet occasionally, until bananas are just softened, about 2 minutes. Remove from heat and let mixture cool completely in skillet. Layer bananas and sauce, pecans, and ice cream in small mason jars or glasses. DO AHEAD: Parfaits can be made 8 hours ahead. Cover and freeze. Let stand at room temperature for 10 minutes to soften slightly before serving.
Preparation Preheat oven to 350°F. Toss pecans, maple syrup, and salt on a parchment paper-lined rimmed baking sheet; spread out in a single layer. Bake until maple syrup is caramelized and pecans are toasted, 10-15 minutes. Let cool completely on baking sheet. Coarsely chop nuts; set aside. Meanwhile, bring whiskey, both sugars, and butter to a boil in a large skillet (do not move pan or mixture may ignite). Turn off heat; stir mixture to dissolve sugar completely. Return to medium heat and simmer until sauce is thickened and glossy, about 2 minutes. Add bananas and cook, swirling skillet occasionally, until bananas are just softened, about 2 minutes. Remove from heat and let mixture cool completely in skillet. Layer bananas and sauce, pecans, and ice cream in small mason jars or glasses. DO AHEAD: Parfaits can be made 8 hours ahead. Cover and freeze. Let stand at room temperature for 10 minutes to soften slightly before serving.