Rhubarb Ginger Upside Down Cake is a charming, old-fashioned dessert baked in a cast iron skillet—just like my grandma used to make. It’s simple to prepare and requires no special equipment, not even a mixer. The warm spice of crystallized ginger pairs beautifully with tart rhubarb for a dessert that feels both familiar and a little exotic. 
Rhubarb can be unpredictable—sometimes mildly tart, sometimes mouth-puckering. The good news is this cake is easy to adjust. If your rhubarb turns out extra tart, see the tips below to balance the flavor.
Rhubarb inspires strong opinions: people typically love it or dislike it. For me it’s nostalgic—my grandmother grew it in her garden and made whimsical desserts with it. This upside down cake is straightforward and moist, reminiscent of a kuchen with fruit baked on top. I usually bake it in a cast iron skillet, but a 9-inch cake pan works just fine as well. 
Tips for handling very tart rhubarb
- Serve slices with vanilla ice cream or freshly whipped cream to mellow the tartness.
- Brush the top of the turned-out cake with warm strawberry jam, honey, or light corn syrup to add sweetness and shine.
Making the cake
- Melt butter in a 9-inch cast iron skillet (or a 9-inch cake pan). Add 1/2 cup brown sugar and about 2 teaspoons finely chopped crystallized ginger. Heat gently and stir until the sugar dissolves. (In the photos a dark brown sugar was used; light or dark brown sugar both work, though light brown will give a lighter color on the finished cake.)
- Carefully add 3 cups fresh rhubarb, cut into 1-inch pieces, arranging it in an even layer over the sugar mixture. The pan will be hot, so use caution.
- In a medium bowl whisk together 3/4 cup buttermilk, 2 eggs, 1/2 cup oil, 3/4 cup brown sugar (the remaining sugar), and 1/4 cup finely chopped crystallized ginger. Add the dry ingredients—1 1/2 cups flour, 1 teaspoon baking powder, 1/4 teaspoon baking soda, and 1/4 teaspoon salt—to the bowl. Lightly stir the top of the dry ingredients to distribute the leaveners, then whisk the dry ingredients into the wet mixture until combined.
- Spoon and spread the batter evenly over the rhubarb so the fruit is fully covered. Smooth the surface with a spatula or the back of a spoon.
- Bake at 350°F (175°C) for about 30–35 minutes, or until the center springs back when touched and a toothpick inserted comes out clean. Remove the skillet or pan and let the cake rest for about 5 minutes on a wire rack. Carefully invert the cake onto a serving plate so the rhubarb topping is revealed. Serve warm or at room temperature.
Note on using a cast iron skillet: skillets are heavy. If you have limited wrist strength or are uncomfortable flipping a heavy pan, use a regular 9-inch cake pan instead for easier handling. Safety first.
Rhubarb Ginger Upside Down Cake
10 minutes
30 minutes
45 minutes
8 slices
Amy D
Ingredients
- 1/4 cup butter
- 1 1/4 cup brown sugar (divided)
- 1/4 cup finely chopped crystallized ginger
- 3 cups fresh rhubarb (cut into 1 inch pieces)
- 1 1/2 cups flour
- 1 teaspoon baking powder
- 1/4 tsp salt
- 1/4 tsp baking soda
- 3/4 cup buttermilk
- 2 eggs
- 1/2 cup oil
- 1 tsp vanilla
Instructions
- Preheat the oven to 350 degrees F.
- Melt the butter in a 9-inch cast iron skillet or cake pan. Add 1/2 cup brown sugar and 2 teaspoons of the chopped crystallized ginger. Heat and stir until the sugar dissolves. (If using a cake pan, melt the butter in the pan by placing it briefly in the oven, then stir in the sugar until it dissolves.)
- Carefully arrange the chopped rhubarb in a single layer over the sugar mixture and set the pan aside.
- In a medium bowl whisk together the buttermilk, eggs, oil, remaining brown sugar, and the rest of the chopped ginger until smooth.
- Add the flour, salt, baking powder, and baking soda to the bowl. Lightly stir the top of the dry ingredients to distribute the leaveners, then whisk the dry ingredients into the wet mixture until combined.
- Spread the batter evenly over the rhubarb, making sure the fruit is fully covered.
- Bake at 350°F for 30–35 minutes or until the center springs back and a toothpick comes out clean.
- Let the cake cool for 5 minutes on a wire rack, then carefully turn it out onto a serving plate.
- Serve warm or at room temperature.
If you enjoy this easy cake, you may also like related fruit kuchen and skillet cake recipes such as Blackberry Kuchen, Peach Kuchen, or Molasses Skillet Cake. 
Did you make this recipe? Leave a note or photo—feedback and reviews are always welcome.