Rhubarb Swiss Roll Cake
Ingredients:
For the cake
- 3 egg whites
- 1 cup sugar, divided
- 1/2 teaspoon cream of tartar
- 3 egg yolks
- 3/4 cup cake flour
- 1 teaspoon salt
- 1 teaspoon vanilla extract
- 1/3 cup milk
- 1/4 cup vegetable or canola oil
For the filling
- 2 cups rhubarb, chopped into 1 inch pieces
- 1/3 cup sugar
- Zest of 1 lemon
- 1 tablespoon salted butter
- 1 cup heavy cream
- 1/4 cup powdered sugar
- 1 teaspoon vanilla extract
Instructions:
- Make the cake. Preheat oven to 350 degrees F. Line a 9x13 sheet pan with parchment paper and spray the parchment paper with a canola-based cooking spray.
- Use a mixer with a whisk attachment to beat the egg whites with the cream of tartar and 1/2 cup of sugar until they form soft peaks. The peaks should just bend over when you pull the whisk away. They should not be completely stiff.
- In a separate bowl beat the egg yolks with the remaining 1/2 cup sugar, vanilla extract, milk and oil. Stir in the cake flour and salt just until combined, and no lumps of flour remain.
- Fold in 1/2 of the whipped egg whites just until combined. Fold in the remaining whipped egg whites until smooth. Try to be as gentle as possible so the air remains in the batter.
- Spread the batter evenly in the prepared baking pan and bake at 350 for 15-18 minutes or until the edges are golden brown and pulling away from the sides of the pan.
- Spread out a thick layer of paper towels on a large surface on the counter and sprinkle with icing sugar.
- Use a knife to loosen the edges of the cake immediately after it comes out of the oven. Flip it on top of the paper towels and turn the cake out onto the paper towels.
- Roll up the cake in the paper towels and place seam down on a wire rack to cool.
- Make the filling. Combine rhubarb, sugar, lemon zest and butter in a medium saucepan over medium heat. Cook for about 5 minutes until rhubarb is tender when pierced with a fork and sugar is dissolved. The rhubarb should still mostly hold its shape and should not be mushy.
- Transfer the rhubarb to a cool dish and place in the fridge or freezer until completely cooled. Do not skip this step, or it will melt the whipped cream in the cake!
- When you are ready to fill the cake, beat the heavy cream, powdered sugar and vanilla extract until soft peaks form.
- Unroll the cooled cake and spread about 2/3 of the whipped cream in an even layer on the cake and top with 2/3 of the rhubarb mixture.
- Gently roll the cake up around the filling, ending with the seam side down. Top with the remaining whipped cream and rhubarb. If you want to see the pretty swirl for serving, slice off the ends.