Recipe: Strawberry-Rhubarb Layer Cake

My sister's birthday is July 1, and we always celebrate on the 4th because the whole family is together.  She has ended up with a lot of very patriotic birthday cakes.  Since most of the time, these involve strawberries and blueberries, she has never complained.

This year, I decided to make her something with some of the bounty from my CSA. I was looking for a strawberry-rhubarb cake recipe online, and most of the recipes I found were dump cakes, and not pretty at all.

I came upon this recipe from Eats Well With Others for Strawberry-Rhubarb Dream Cake and knew that I had to make a version of it for my sister's birthday cake.  The recipe was just what I was looking for - fancy and beautiful.  I tweaked the recipe some to suit our needs, but overall, I couldn't be happier with the results.  It was festive, moist, and absolutely delicious.

Fresh rhubarb

Fresh strawberries

Here is my version - though I doubled the recipe, I will post a single recipe because doubling was HUGE. There was too much batter for my poor little mixer.  I had to mix in the last bit by hand in a larger bowl. The recipe I am posting would be enough for one half sheet pan, or two 8x11 pans.  If you make it in one half sheet pan (as I would recommend - I just got a foil one at the grocery store), cut the finished cake in half for layering.

Strawberry Rhubarb Layer Cake
(Adapted from Eats Well With Others)

Cake:
1 c butter, softened
2 c sugar
5 eggs
1 Tbsp vanilla extract
1 c cake flour
2 c all-purpose flour
1 Tbsp baking powder
1 tsp salt
1 1/4 c buttermilk (or 1 1/4 c milk with 1 Tbsp lemon juice stirred in)
2 c diced rhubarb

Filling:
1 quart fresh strawberries, hulled and chopped into small pieces (several strawberries set aside and halved for topping)
zest of 1 lemon
1/4 c sugar

3 cups heavy cream
1 cup mascarpone
1 Tbsp vanilla extract

Frosting:

Cool Whip with vanilla pudding mix mixed in, or Cool Whip Frosting (I used the Cool Whip frosting and it was fantastic)

Preheat the oven to 350 F. Line a half sheet pan with parchment paper and spray with cooking spray with flour in it, or cooking spray and dust with a bit of flour.

Cream together the butter and sugar until light and fluffy. Add the eggs, one at a time, and the vanilla.
In a separate bowl, whisk together the flour, baking powder and salt. Add a third of the flour mixture to the butter-sugar mixture, stirring until just combined.  Add in half of the milk. Repeat with the second third of the flour and the remaining buttermilk. Add in the remaining flour and still until just incorporated. Fold in the rhubarb.

Folding in the rhubarb

Spread batter evenly in the pan, leveling with a spatula.  Bake for 30 minutes, or until a toothpick inserted in the center comes out clean.  Cool in the pan, unless you have a very large cooling rack that will hold the whole half sheet cake.  Do not fill and layer until the cake is completely cool.

To make the filling, mix the chopped strawberries with lemon zest and sugar.  Allow to sit for 10 minutes. Meanwhile, whip together the heavy cream and mascarpone with vanilla until stiff peaks form.

Cut the half sheet cake in half lengthwise, so that you have two equal rectangles.  Spoon the juices from the macerated strawberries onto the bottom layer and brush to coat.  Spread the remaining strawberry mixture evenly over the cake, then top with the mascarpone cream.  Level the filling with a spatula, and freeze for 10 minutes to set.  Remove from freezer and top with second cake layer.  

First time seeing this at the store, and I got it on a whim - it's great!

Frost with Cool Whip mixed with pudding mix, or with Cool Whip Frosting.  Decorate the top with strawberries and blueberries.  Serve chilled if possible.