Place butter in 8 inch cast iron pan and melt in oven preheated to 350 degrees. The shelf should be about 6 inches from the top heating element. When butter has melted remove from oven and let cool a couple of minutes. Brush butter up sides of pan.
Add vanilla and cinnamon to maple syrup and pour into cast iron pan. Stir to mix syrup and butter.
Slice bananas evenly about an eighth of an inch thick. (Bananas will shrink as they bake.)and spread over the butter/syrup mixture. Sprinkle chopped walnuts over the bananas.
Make your favorite pancake batter and gently spoon to cover the bananas. Bake in oven for approximately 30 minutes or until pancake is brown and set.
Remove from oven and let sit for about 5 minutes. Use a spatula or knife around edges to loosen from sides of pan. Invert pancake onto a large platter and slice into either 6 or 8 slices. To serve, sprinkle with confectioner's sugar and add a couple of strawberries or raspberries for color. This recipe can be cut in half and made in two small tapas pans if you are serving only a few people.