Rhubarb used to be this very mysterious fruit to me. Or was it a vegetable? I’d heard of the classic rhubarb-strawberry pie combination but only a few years ago when I asked an American guy I was dating what his favorite dessert was. Maybe it was this memory or the interesting fact I learned that the leaves were poisonous that made me put it in a birthday pie I made for an article for Inspirelle. Of course I didn’t put the leaves in the pie! In normal Molly behavior, I just chopped the stalks up, threw it in and crossed my fingers. The pie was fantastic and always comes to mind when I start seeing those beautiful splashes of pink and green in the market.
That’s the joy of cooking with the seasons. Kind of like when you get tired of winter, and excited for spring, I was beyond ready to move on from cooking with butternut, pumpkin, and potatoes. So just like when blood oranges made an appearance a couple of weeks ago, I jumped when I saw rhubarb and bought at least a couple of stalks each weekend.
Rhubarb allows for a lot of creativity in baking. You have to be careful that it’s cooked enough to avoid the stringiness and balance out the tart with sweet.
For this cake, I thought of everything I loved, rhubarb with a lemon cake and ginger icing. Fresh flavors with the moist but slightly dense deliciousness of the cake.
The idea for the rhubarb on top came from a rhubarb tart I made that I had a base of financier- the wonderful browned butter almond cakes you find in France. The rhubarb was roasted first and then laid on top of the batter before baking. But what would happen if I put this on top of a sponge cake? Would it rise? Did it matter if it didn’t rise all that much? So in a very un-pastry chef like move, I just went with it and again, crossed my fingers.
The top was stunning. I could have chopped up the rhubarb and folded it in but I would have entirely missed the artwork the rhubarb made with the cake beautifully browned in between the stalks. And the taste: dense but in a nice way and not too dense; moist from the rhubarb on top; and delightfully delectable. The rhubarb went perfectly in the cake, and was a lovely taste of tart. But because it was just one layer on top of each cake, it was overpowering and paired beautifully with the ginger-vanilla icing.
Rhubarb Stripe Cake with Lemon and Ginger
Makes three 8" cakes or two 9" cakes. Keeps for 3-4 days in the refrigerator. Before serving let warm to room temperature for the best taste.
- 3-4 rhubarb stalks
- 400 g All Purpose Flour (T45 or T55)
- 2 tsp baking powder
- 1 tsp salt
- 335 g unsalted butter (room temp)
- 430 g granulated sugar
- zest of one lemon
- 2 tbsp lemon juice
- 235 g whole milk
- 8 egg whites (275g)
Ginger Vanilla Icing
- 2 tsp fresh ginger (grated/zested)
- 1/2 tsp vanilla extract
- 200 g unsalted butter (room temp)
- 500-700 g powdered sugar (add to correct texture)
- 2 tbsp milk (whole or otherwise)
The Roasted Rhubarb
Start with the rhubarb. Preheat the oven to 375F/190C. Trim the tops and bottoms off the rhubarb stalks and give them a little rinse. If they're large stalks cut in ribbons that are 1-1.5 cm wide. Cut into smaller pieces (the length of the cake pan more or less). Place on a slipat, parchment, or stick-proof baking sheet and sprinkle with granulated sugar. Bake until tender. Timing will depend, so it's best to set a timer at 15 minutes and then give it a test by sticking a knife into one or two pieces. If the knife goes in easily, they're done.
The Lemon Cake
While the rhubarb is roasting. Start on the cake. In a bowl, whisk together the flour, baking powder and salt.
In the bowl of an electric mixer, put the sugar and lemon zest. Using your fingers, rub them together to release the oil from the zest to help pronounce the lemon flavor. Add the butter to the bowl and cream together.
Alternate adding the milk and dry mixture to the bowl, starting with the dry. Then mix in the lemon juice.
Whip the egg whites to stiff peak and then gently fold them into the batter.
Butter and flour your cake tins, placing a parchment circle at the bottom. Fill about halfway with batter and then top with the cooled roasted rhubarb. (If it's still really hot, then put it on a plate in the freezer for a couple of minutes.)
Bake at 350F/175C for 30-40 minutes. The cake will be nicely browned, and the center firm. It's hard to tell with the rhubarb, so make sure you touch the middle to make sure it is cooked. Cool completely.
The Ginger & Vanilla Frosting
In an electric mixer fitted with a paddle, beat the butter with the ginger until soft. Mix in the vanilla.
Add the powdered sugar a bit at a time until the mix is extremely thick and lighter in color, then add a tablespoon of milk to loosen it up. Watch the consistency. Add a little more powdered sugar/milk if needed. Test if needed, it should be easy to spread, but still easily holding its shape.
Assemble by placing one cake layer, rhubarb up, and then using a piping bag or plastic bag, not fitted with a tip, pipe the icing on top. Or place a huge blob in the center and then smooth it out. What you want to avoid is smoothing too thin or a layer over the rhubarb as it might create too much pull on the rhubarb, making it come out of the cake. Putting a little icing distance in between the rhubarb and your knife helps keep this from happening. Top with the other cake layer or layers, and little dollups of icing and fresh strawberries! Enjoy!