Rhubarb Upside Down Cake
Author: 
Yield: 1 9-inch cake
 
Ingredients
For the Topping
  • 4 tablespoons unsalted butter, very soft
  • ½ cup all-purpose flour
  • ¼ cup sugar
  • ¼ teaspoon salt
For the Cake
  • 1½ sticks (12 tablespoons,) unsalted butter, room temperature, plus more for buttering pan
  • 1 pound rhubarb, trimmed and cut on a very sharp diagonal about ½ inch thick
  • 1¾ cups sugar
  • 2 teaspoons vanilla bean paste, extract (or vanilla beans scraped from a pod.)
  • 1½ cups all-purpose flour
  • 1½ teaspoons baking powder
  • 1½ teaspoon salt
  • zest of 1 lemon
  • 2 large eggs, room temperature
  • 1 cup sour cream
Instructions
  1. Preheat oven to 350F.
For the topping:
  1. Use a fork to stir together the soft butter, flour, sugar and ¼ teaspoon salt until crumbly. Set aside.
For the cake:
  1. Butter and flour your 9 inch pan. Cut 4 tablespoons of butter into bits and dot the bottom of the pan. Toss the rhubarb with ¾ cup sugar and 1 teaspoon vanilla bean paste. Let it sit for a couple minutes and then toss again. Spread rhubarb into the bottom of the pan.
  2. Whisk together flour, baking powder, and 1½ teaspoons salt, set aside. Cream the remaining stick of butter and cup sugar with a mixer on medium speed until pale and fluffy.
  3. Add in zest and vanilla. Add eggs, 1 at a time, until incorporated, scraping down sides of bowl.
  4. Add the flour mixture in 3 additions, alternating with sour cream, until smooth. (Don't overmix!) Spread evenly over rhubarb. Sprinkle the topping over the batter.
  5. Bake in the middle rack on top of a cookie sheet, until a toothpick inserted into the center comes out clean and top springs back when touched, about 1 hour, depending on pan size.
  6. Let cool for 10 minutes, then run a knife around the edge and invert cake.
Notes
*I recommend a 9-inch spring form lined on the inside with foil, a bundt pan, or a 9 inch cake pan with extra high sides!

Recipe barely adapted from Martha Stewart
Recipe by The Baker Chick at https://www.thebakerchick.com/rhubarb-upside-down-cake/