Preheat oven to 350 degrees. Spread pecans on a baking sheet and bake for 10 minutes or until golden. Let cool, then coarsely chop 1/2 cup. Set the reminder aside. Lower the oven temperature to 225 degrees.
Preheat a waffle iron. In a large bowl, whisk the flour, cornmeal, baking powder and salt. In a small bowl, combine milk, egg yolks, 3/4 teaspoon vanilla and 6 ounces of melted butter. Stir the liquid into the dry ingredients just until moistened. Lumps are okay. Slice 1/2 of the banana slices into quarters. Fold the bananas into the batter.
In a clean bowl, beat the egg whites at medium speed until frothy. Increase the speed to high and beat until firm peaks form. Add the sugar and beat until the whites are stiff and glossy. Fold the whites into the batter until no streaks remain.
Pour batter into prepared waffle iron and bake until the waffle is golden. Transfer the waffle to an oven rack to keep warm.
In a large skillet, combine corn syrup, brown sugar, maple syrup, and remaining butter. Bring to a boil over medium-high heat. Reduce heat and simmer for 2 minutes. Add remaining bananas and vanilla extract plus the rum extract. Coat bananas with the syrup mixture and simmer 1 minute. Spoon over waffles. Garnish with pecans and sweetened whipped cream. Serve immediatlely.