Easy Bananas Foster French Toast

Name: Easy Bananas Foster French Toast
Ingredients: 1/2 cup pecans; 1 (1-pound) unsliced loaf challah bread or brioche; 1 1/2 cups whole milk, half-and-half, heavy cream, or any combination; 6 large eggs; 2 tablespoons maple syrup; 1 tablespoon vanilla extract; 1/4 teaspoon kosher salt; 4 tablespoons unsalted butter, divided; 2 slightly under ripe medium bananas; 6 tablespoons unsalted butter; 2/3 cup packed dark or light brown sugar; 1/2 teaspoon ground cinnamon; 1/8 teaspoon kosher salt; 1/3 cup heavy cream; 2 tablespoons dark rum (optional); 1 teaspoon vanilla extract