Rhubarb Banana Skillet Cake
1 pound fresh rhubarb stalks (see note)
2/3 cup + 1/4 cup brown sugar, firmly packed
1/3 cup + 1 T. vegetable oil
1 medium very ripe banana (see note)
1 medium orange
1.5 ounces fresh ginger root
1 T. pure vanilla extract
2 tsp. powdered ginger
1.25 cups all-purpose flour
2 tsp. baking powder
1 tsp. baking soda
1/2 tsp. salt
1/2 cup boiling water
To yield the prettiest cake possible, pick rhubarb that’s the deepest pink in color you can find, both inside and outside of the stalks if possible. For best results, use a banana that’s extremely ripe, dark and soft. This will be easier to work with and will provide the maximum moistness and pleasant sweetness in the cake. Rinse rhubarb; trim and discard tough ends. Slice stalks in half once crosswise, and then once lengthwise (unless they are already very narrow). Set aside. Using 1 T. oil, thoroughly coat the interior of a 9 to 10 inch ovenproof skillet such as cast iron. Place rhubarb in skillet in a single parallel pile, trimming ends to make it fit if needed. Top rhubarb with 1/4 cup brown sugar. Place pan over medium-low heat and cover with lid. Cook 5 minutes, remove lid, and use heatproof tongs to gently rotate top and bottom layers of rhubarb. Cover and cook another 5 minutes. Rhubarb should be very soft and juicy. Remove lid, remove pan from heat, and set aside. Preheat oven to 350 F. Peel the banana and mash it well with a fork until no longer lumpy. Measure the mashed banana; it should yield 1/3 to 1/2 cup. (If yours yields more than this, set aside extra and use for another purpose. If less, add a bit more oil to make at least 1/3 cup total.) Rinse, dry, and finely zest the orange; set zest aside. Juice the orange and measure out 1/4 cup juice, discarding any seeds. Set juice aside. Peel and finely grate a piece of fresh ginger root (see note); then measure out 2 tsp. grated ginger. Heat a kettle of water. In a large bowl, beat 2/3 cup brown sugar and 1/3 cup vegetable oil. Add the vanilla, mashed banana, and grated ginger. Mix well. Sift over the mixture: powdered ginger, flour, baking powder, baking soda, and salt. Begin to mix (batter will be thick), alternately adding the 1/4 cup orange juice and 1/2 cup boiling water. Beat well, scraping sides and bottom of bowl with spatula. Finally, fold in the orange zest until evenly distributed. Before adding batter into skillet, gently rearrange rhubarb, pulling it to edges of the pan to ensure the bottom of the cake is completely covered in a single layer of rhubarb – preferably with most of the stalks going in the same direction. Slowly pour batter over rhubarb and place skillet in oven. Bake for 25 to 30 minutes, or until a toothpick inserted in the center of the cake comes out batter-free (a few moist crumbs are OK). Carefully remove from oven. Let sit at least an hour or until pan is cool enough to grasp. Just when ready to serve, loosen edges of cake with a knife, and invert onto a plate. If cake has completely cooled or is the least bit stubborn about coming out of pan, be sure to place skillet over medium heat on stovetop for 30-60 seconds before flipping. The cake is best served the day of baking, but feel free to store it covered and refrigerated, eating within a day.