Lemon Vertical Roll Cake + Rhubarb Rose Frosting
Serves: one 6" cake
 
This cake is somewhat on the smaller side, though it could still feed 8-12 people with small slices. If you would like a larger cake, double the recipe and cut each sheet into two long strips instead of 3, so that you end up with a total of 4 cake strips to roll. This will give you a cake about 8-9" in diameter instead of 6".
Ingredients
  • FOR THE SPONGE CAKE;
  • 8 large eggs, separated
  • ⅔ cup + 2 tablespoons + 1½ tablespoons Raw Cane Sugar
  • 1 tablespoon Lemon Juice
  • zest of 1 large Lemon
  • ½ cup + 1 tablespoon All-purpose Flour
  • ⅛ teaspoon Salt
  • Powdered Sugar, for dusting
  • FOR THE RHUBARB ROSE FROSTING:
  • 2 stalks Rhubarb(the darker red, the more pink the frosting will be)
  • ¼ cup Water
  • 1 cup Grass-fed Butter, room temperature
  • 1 pound Powdered Sugar
  • ½ teaspoon Rose Water
  • 1-3 teaspoons Lemon juice
  • FOR THE RHUBARB ICING:
  • 1 cup dark red Rhubarb, sliced
  • ⅓ cup Water
  • Powdered Sugar
Instructions
  1. FOR THE SPONGE CAKE:
  2. Preheat the oven to 400 degrees. Line a baking sheet (1/2 sheet pan) with parchment paper(parchment should hang over the sides).
  3. Place the egg whites in a large bowl and bead on medium/high speed with an electric mixer until soft peaks form. Slowly add in 1½ tablespoons of sugar . Continue beating until stiff peaks form. Set whipped egg whites aside.
  4. In another large bowl, using the same beaters you used to beat the egg whites, beat the egg yolks with the remaining ⅔ cup + 2 tablespoons of sugar, lemon juice, lemon zest, and salt. Beat for about 3 minutes, or until the egg yolks have thickened and turned a pale yellow.
  5. Sift the flour over the egg yolk mixture and fold in until just barely combined.
  6. Add ⅓ of the beaten egg whites to the yolk mixture and fold in just until incorporated. Gently fold in the remaining egg whites until the batter is smooth.
  7. Spoon the batter into the prepared baking sheet and bake in the preheated oven for 13-15 minutes, or until the top of the cake is just golden brown.
  8. Remove from the oven and let cool for 5 minutes.
  9. Dust the top of the cake with powdered sugar and cover the cake completely with a clean tea towel. Fip the cake over so that it is on top of the towel and remove the baking sheet. Carefully peel the parchment paper off of the cake. Trim any edges as needed to keep the cake lines clean and straight. Starting at the shorter edge of the cake, roll up the cake(along with the towel) and set the rolled cake aside to cool(it will be completely enveloped by the towel.
  10. Once the cake is cool, unroll. Using a pizza roller or knife, cut the cake(on the long side) into three even strips.
  11. Spread each strip with a layer of the rhubarb frosting, leaving about ½ of the frosting to frost the tops and sides of the cake. Take one of the frosted strips and, starting at the short end, gently roll it up to form a sort of barrel. Position the rolled cake so that the edge of the cake lines up with the next strip of cake and roll so that the barrel becomes even larger. Repeat with the last strip of cake so that you end up with one large barrel shaped coil of rolled cake.
  12. Place the cake(coiled side down) on a serving dish and refrigerate for 1 hour(this is just to help it firm up so that frosting will be easier). Remove and frost the tops and sides with the remaining frosting.
  13. Carefully pour the icing on top of the cake and use a knife to gently spread it toward the sides, helping it to lightly drop over the edges.
  14. Cut into slices and serve!
  15. FOR THE RHUBARB ROSE FROSTING:
  16. Slice the rhubarb and place in a small saucepan along with the water. Bring to a simmer and cover until rhubarb is softened, 1-2 minutes. Remove the lid and stir the rhubarb to help break it down. Continue to cook until the pan is dry and no liquid seeps out from the rhubarb. Remove from heat and let the rubarb cool completely.
  17. In a large bowl, beat the cooled rhubarb and butter together until combined. Beat in the powdered sugar until mixture smooth. Beat in the rose water.
  18. Add lemon juice to the frosting until the desired consistency is achieved. Store any unused frosting in an airtight container in the fridge.
  19. FOR THE RHUBARB ICING:
  20. Add the rhubarb and water to a saucepan and bring to a simmer over medium heat. Let cook, stirring occasionally, until the rhubarb is completely broken down and soft. Remove from heat and run the mixture through a fine mesh sieve, collecting the liquid and puree in a small bowl. Whisk in powdered sugar, a little at a time, until a thick icing is achieved.
Recipe by The Kitchen McCabe at https://www.thekitchenmccabe.com/2018/04/29/lemon-vertical-roll-cake-rhubarb-rose-frosting/