Coat 12 muffin cups with nonstick cooking spray. Place the bread cubes into the muffin cups, pressing firmly if necessary. Whisk the eggs in a medium bowl until blended. Whisk in the milk, sour cream, 2 tablespoons brown sugar, flour and maple flavoring. Pour over the bread in the muffin cups. Sprinkle with the pecans. Cover and refrigerate at least 30 minutes or overnight. Heat the oven to 350 degrees. Bake, uncovered, for 30 to 35 minutes or until a knife inserted in the center comes out clean. Let stand for 10 minutes. Meanwhile, combine 1/3 cup brown sugar, melted butter, and maple syrup in a small saucepan. Bring to a boil over medium-low heat. Cook, stirring, until the sugar is dissolved. Remove the French toast from the muffin cups and serve drizzled with the warm sauce.