Rhubarb Upside-Down Cake
One of the easiest cakes you’ll ever make! The rhubarb goes in the pan first, followed by a simple butter cake, and topped with an almond streusel (which becomes the bottom when you turn it out of the pan). With butter in every layer, what’s not to love?
Recipe
Streusel:
1/2 c. all-purpose flour
1/2 c. sliced almonds
1/4 c. sugar
4 T. unsalted butter, melted
1/4 tsp. salt
Rhubarb:
3/4 c. sugar
1-1/2 tsp. cornstarch
1 tsp. grated lemon zest
1 lb. rhubarb, trimmed and cut into 1/2-inch pieces
2 T. unsalted butter, melted
Cake:
1 c. all-purpose flour
1-1/2 tsp. ground cardamom
1 tsp. baking powder
1/2 tsp. salt
1 c. sugar
2 large eggs
6 T. unsalted butter, melted and cooled
1/2 c. sour cream
1 tsp. grated lemon zest + 1 T. juice
1 tsp. vanilla extract
2 T. red currant jelly
Adjust the oven rack to lower-middle position and preheat to 350-degrees. Grease an 8-inch square baking pan, line bottom with parchment paper, and grease parchment.
For the streusel: Stir all ingredients in a medium bowl until well combined. Set aside.
For the rhubarb: Whisk sugar, cornstarch and lemon together in a large bowl. Add the rhubarb and stir well to coat. Drizzle with melted butter and stir to incorporate. Transfer rhubarb mixture to the baking pan and press pieces into bottom of pan, making sure there are no large gaps.
For the cake: Whisk flour, cardamom, baking powder and salt together in a medium bowl and set aside. Whisk sugar and eggs in a large bowl until thick, about 45 seconds. Whisk in the cooled melted butter until combined. Add sour cream, lemon zest and juice, and vanilla. Whisk until combined. Add flour mixture and whisk until just combined. Pour batter into pan and spread evenly over the rhubarb. Break up the streusel with your hands and sprinkle evenly over the batter.
Bake 45-50 minutes until a toothpick inserted in center comes out clean.
Transfer pan to a wire rack and let cool for 20 minutes. Run knife around edges of pan to loosen cake, then invert onto a serving platter. Let cool for 10 minutes.
Heat the currant jelly until fluid, about 20 seconds in the microwave, or in a small pan on the stove using a little whisk or spoon. Using a pastry brush, gently dab jelly over the rhubarb topping. Serve warm or at room temperature.