Strawberry Rhubarb Cream Cake

Nothing says spring like strawberries and rhubarb.  After a long season of winter, the bright pop of color and tart acidity of this fruit combination is more than welcome.  It's time for our annual spring pies, galettes and shortcakes!

This is a pretty simple cake but one that really delivers on the promise of spring.  It starts with a basic white cake.  I've tried lots of white cake recipes but they always seem to fall just short of what I'm looking for.  Sometimes they're too dry or too sweet or too dense or crumbly.  I set to work on a basic white cake formula and with just a few little tweaks and a couple of test runs, I'm pleased with these results.  The cake has a soft and tender texture with an open crumb.  The flavor is subtle and wonderful, just the sort of backdrop for all your favorite fillings and frostings.

The rhubarb in this recipe is cooked briefly on the stovetop with some sugar, orange zest and vanilla, flavors that really complement both fruits.  The strawberries are sliced and folded in fresh to brighten the mix.  It's an easy compote to layer in the middle of the cake.  Then the whole thing is slathered in whipped cream.  Light, fresh and simply delectable.

Happy spring!



Bench notes:
- It's important to use cake flour for this recipe to produce a lighter and more tender cake.  I buy it at my local bulk grocer where it's much less expensive than the box at the supermarket. You can also make your own cake flour using regular flour and cornstarch, which inhibits the formation of gluten.  Here is the basic formula: 1 cup of cake flour = 1 cup all-purpose flour minus 2 tablespoons plus 2 tablespoons cornstarch.  For the 1 1/2 cups of cake flour in this recipe, measure 1 1/2 cups of all-purpose flour and remove 3 tablespoons.  Add 3 tablespoons of cornstarch and sift a couple of times to be sure it's completely blended.
- This technique for mixing cake batter is called the "two-stage" method made popular by Rose Levy Beranbaum in The Cake Bible.  It's different from the creaming method in that all the dry ingredients are mixed with the butter and some of the liquid.  This mixture gets beaten for 1 1/2 minutes and then the eggs, vanilla and remaining liquid are added in three stages and mixed for 20 seconds after each addition.  The creaming method results in more aeration of ingredients and therefore cakes made using that method usually have a stronger structure and turn out with a higher rise.  This two-stage method results in less gluten development and yields a more tender cake with a delicate crumb, exactly what we're looking for in a basic white cake.
- For those who don't own a scale, I base my metrics on the "dip and sweep" method of measuring flour with the following important condition: Flour gets very compacted as it sits in our cupboards.  So when measuring flour by volume, it's important to first take a fork or a whisk and fluff the flour thoroughly to aerate it before each dip of your measuring cup.  Overfill it just a bit and then use a spatula to level the cup.  So to measure by weight, my 1 cup of all-purpose flour = 5 oz (142 grams).  My 1 cup of cake flour = 4 oz (113 grams).
- "Room temperature" butter means the chill has been take off and it's pliable but not soft to the touch.
- The cooked rhubarb will taste sweet but the added strawberries don't have any additional sugar.  You may want to use less sugar if your strawberries are sweet.
- I recycle a 3" piece of dried vanilla bean from my vanilla sugar jar to use for this compote.  If you don't have a vanilla bean, substitute 1/4 teaspoons vanilla.
- If you don't have creme fraiche,  just use an additional 2 tablespoons of heavy cream.
- What's the difference between heavy cream and whipping cream?  Heavy cream contains 36% milk fat; whipping cream has 30%.  For finishing a cake like this, use heavy cream because it whips up with a stronger loft and will hold its shape longer than whipping cream without weeping.  Cream whips best when it's very cold.
- Use a serrated knife and a gentle sawing motion to cut the cake into two layers. Start by making a small 1" cut into the side of the cake all the way around.  Then bring your knife around again, sawing a little deeper.  The cake will be cut in half very quickly.  If you try to cut straight across in one fell swoop, you'll wind up with a lot more crumbs.  Once the cake has been cut into two layers, I use a removable tart pan bottom to lift off the top half layer and set it aside.
- The cake can be made a day ahead and stored in an airtight container at room temperature.
- For a simpler presentation, dollop the cream on top of the cake and serve the compote on the side.  Or prepare individual servings by layering cake, fruit and cream in parfait glasses.
- For a larger cake, double the recipe and use two 9" cake pans.  These will bake for a bit shorter time, about 25 - 28 minutes.  You'll probably need about 1/3 C more whipped cream and a few more strawberries.
- Another very delicious cake along the same lines: Angel Food Cake Roll with Strawberries & Cream.  Or if you prefer chocolate: Chocolate & Balsamic Strawberry Cream Cake.



Strawberry Rhubarb Cream Cake
Serves 8

White Cake
3 large (3 oz) egg whites @ room temperature
1/2 cup (4 oz) whole milk @ room temperature, divided
1 teaspoon vanilla extract
1 1/2 cups (6 oz) cake flour
1 1/2 teaspoons baking powder
1/2 teaspoon salt
4 oz (8 tablespoons) unsalted butter @ room temperature
3/4 cup + 2 tablespoons (6 1/4 oz) sugar

Strawberry Rhubarb Compote
4 stalks (about 9 oz) rhubarb, cut into 1/2" pieces
1/4 cup + 2 tablespoons (2 3/4 oz) sugar
zest of 1/2 orange
1/3 vanilla bean or 1/4 teaspoon vanilla extract
12 oz fresh strawberries

1 cup (8 oz) cold heavy cream
2 tablespoons (1 oz) cold creme fraiche
1 1/2 tablespoons sugar
1/2 teaspoon vanilla extract

Preheat oven to 350 degrees F.  Lightly grease an 8" x 2 1/2" cake pan and line the bottom with a circle of parchment.

Whisk together egg whites, 1/4 cup milk and vanilla and set aside.

Combine cake flour, baking powder and salt in a mixing bowl and mix on low speed for 30 seconds to blend.  Cut the butter into 1/2" pieces and add to the flour mixture with the 1/4 cup remaining milk.  Mix on low speed until moistened.  Increase to medium speed and beat for 1 1/2 minutes.  Scrape down the sides and bottom of the bowl.  Gradually add the egg white and milk mixture in 3 batches, beating for 20 seconds after each addition to incorporate the ingredients and strengthen the structure.  Scrape the batter into the prepared pan and spread evenly to level it.

Bake until golden brown and a tester inserted into the center comes out clean, 30 - 32 minutes.  Place on a rack to cool for 10 minutes.  Run a knife around the edge to loosen. Invert the cake.  Carefully remove the parchment and invert again.  Cool completely.

For the compote, place the sliced rhubarb in a saucepan with the sugar, orange zest and vanilla bean.  Cook over medium low heat for about 10 minutes or until the fruit softens but still holds its shape.  Take off the heat and remove the vanilla pod.  Slice the strawberries into bite-sized pieces and toss with the rhubarb.

To assemble, whip the cold cream, creme fraiche, sugar and vanilla to a medium stiff peak.  Chill until ready to use.

Place the cake on a cake board, removable tart pan bottom or a serving platter.  Slice the cake in half horizontally and set the top half aside.   Spread the fruit compote on the bottom half to within 1/2" of the border.  Place the top of the cake over the fruit and press gently to secure.  Slather the cake with the whipped cream and chill until ready to serve.