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5 from 11 votes

Rhubarb Upside-Down Cake

A bright, moist and vibrantly colorful spiced rhubarb upside-down cake that’s bursting with flavor and celebrates the best of spring and summer rhubarb bounty, easily made all in a food processor!
Prep Time35 mins
Cook Time1 hr 10 mins
Total Time1 hr 45 mins
Course: Dessert
Cuisine: Californian
Keyword: Rhubarb Cake, Spring Dessert, Summer Dessert, Upside-Down Cake
Servings: 10
Author: Daniela Gerson

Ingredients

For the Rhubarb Topping

  • 6 stalks rhubarb about 1.5 pounds
  • ¼ cup unsalted butter
  • ½ cup light brown sugar
  • zested & juiced 1 orange divided
  • 1/4 teaspoon ground ginger or 1 tablespoon of grated fresh ginger
  • ½ teaspoon cardamom
  • 1 teaspoon kosher salt

For the Cake

  • 1 ½ cups all-purpose flour
  • 1/2 teaspoon cardamom
  • 1 ½ teaspoon baking powder
  • 1 teaspoon kosher salt
  • 3/4 cup pistachios
  • 8 tablespoons butter 1 stick, room temperature
  • ½ cup white sugar
  • 1/4 cup brown sugar
  • 2 eggs
  • zest & juice orange remaining
  • 1 cup Greek yogurt
  • 1 teaspoon vanilla extract

Instructions

For the Rhubarb Toppings

  • Preheat oven to 325 F degrees.
  • Use a 9-inch cake pan or a 9-inch cast iron skillet. Cut the rhubarb to fit your  pan. This takes a bit of trial and error. After aligning, take the rhubarb out and set aside in the correct order to you know how to put the pieces back in. If you have leftover rhubarb you can cut it in 1/2" chunks and incorporate into the cake batter. 
  • Melt the butter in a small saucepan on the stove and add the brown sugar, on one half of the orange zest & juice, cardamom, ginger and salt. Heat and stir until the sugar is dissolved and the mixture begins to bubble around the edges. Pour this sugar mixture into the cake pan, then line the rhubarb into the pan as you just trimmed it. Set the pan aside while preparing the cake batter.  

For the Cake

  • In a medium bowl, combine the flour, cardamom, baking powder and salt with a whisk. Set aside. 
  • In a food processor fitted with the knife blade, finely grind the pistachios. Change the blade to the dough blade. Add butter and sugar and beat in processor until light and creamy. mix in eggs, one at a time, stopping to scrape down sides. Add the remaining orange juice and zest, vanilla and the yogurt. Mix well. Add the four mixture and pulse just to combine, again scraping the bowl to make sure the batter is uniform. Briefly mix in any reserved rhubarb chunks. 
  • Transfer batter to pan, on top of rhubarb stalks, and smooth top of batter. 
  • Bake in oven for 1 hr. and 10min.  The top should be browned and the edges bubbly. A cake tester inserted in the center will be clean. 
  • Cool the cake for 5 minutes then run a small sharp knife around edges. Place a plate on top of the cake pan and invert. Slowly lift the cake pan away. 
  • I prefer the cake warm with lightly sweetened and freshly made whipped cream or vanilla ice cream, but it can also be served at room temperature, as is. 

Notes

  • When choosing rhubarb, looks for stalks with the deepest shades of red near the base and ones that are firm and crisp.
  • Discard the toxic leaves!
  • Aligning the rhubarb: this take a bit of trail and error! I align the rhubarb in a row and place the cake pan on top to get an idea of where to trim. Snugly fitting in as many rows of rhubarb as the cake pan will allow, often putting a piece in only to take out and trim a bit more. It’s a bit like rhubarb Tetris!
  • If you don’t have a cake pan, an ovenproof skillet can work as well.
  • Be patient when turning the cake pan. May take several minutes for it to release.
  • Leftovers can be stored in an airtight container at room temperature for up to 3 days.
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