Yellow Cake with Raspberry Buttercream Filling and Chocolate Buttercream Frosting

My niece Kate turned 4 not so long ago.  This year, she had a family party and a kid party.  Clearly two birthday cakes were required.  The children’s party had a butterfly theme, and hence a butterfly cake.  And it had to be chocolate.  But more about that later.

For the family cake, we went with flowers.  Chocolate frosting was still an absolute necessity, but Kate decided to try something different for the cake itself.  We went with yellow cake, raspberry buttercream filling. chocolate buttercream frosting, and yummy vanilla flavored frosting roses.  Don’t worry, the buttercream can be made in one batch, then split up and flavored with raspberry and chocolate.  The roses can also be made a couple of days ahead of time. The raspberry and chocolate buttercreams are light and creamy and go together extremely well.  The yellow cake is very moist.

I was so worried about keeping the buttercream from melting during the 3 hour drive to New York City, that I totally forgot what a roller coaster the Taconic highway with its potholes and bumpy ridged roads can be.  Luckily, I had the cake in a bakery box, packed tightly into a soft cooler bag, placed snugly into a larger cooler, wedged between a suitcase and other assorted packages in the trunk of my car.  I was thrilled to arrive on the upper west side, cake unscathed.  Phew!

And most importantly, the birthday girl loved her cake!

Yellow Cake (adapted ever so slightly from Shirley Corriher's Bakewise)

8 tablespoons (i.e. 1 stick or 4 ounces) unsalted butter cut in small pieces

3 cup sugar

4 teaspoons vanilla
2/3 cup canola oil

6 large egg yolks

4 large eggs

3 1/2 cups cake flour

3 1/2 teaspoons (i.e. 1 Tbsp + 1/2 tsp) baking powder

1 teaspoon salt
2/3 cup buttermilk
1 cup heavy cream

Preheat the oven to 350F at least 20 minutes before baking.  Spray 3 8" pans with baking spray, line with parchment, and spray again.  (You can also make 2 9" layers if your pans are a full 2" tall.)

Soften the butter in a mixer on medium speed.  Beat until light in color, about 3 minutes (warning: it's not so easy to beat such a small amount of butter, but give it your best).  Add the sugar, and beat until very light.  Keep the bowl cool, and scrape the sides of the bowl occasionally (or use a beater blade).

Beat in the vanilla.  On medium, mix in the oil.

On low, beat in the yolks, then the whole eggs, one  at a time, mixing just until combined. 

Whisk together the flour, baking powder, and salt until fully combined.  Add about half the dry ingredients to the batter, and mix on low until just combined.  Add in half the buttermilk, still on low, and add the rest of the dry ingredients until just combined.  Finish with the remaining buttermilk.  

In a separate bowl (make sure it's cold), whip the cream to soft peaks.  Beat just a little longer.  Stir in 1/4 of the whipped cream into the cake batter to lighten.  Gently fold in the rest of the whipped cream.  Pour into the prepared pans.  Drop the pans (just a few inches) to knock out air bubbles.

Bake for 35-40 minutes until a toothpick just comes out clean.  The cake should just pull away from the sides when you remove it from the oven.  Cool in pan, on a rack, for about 10 minutes, then invert onto parchment paper and remove pan.  Cool completely.

Swiss Meringue Buttercream Frosting

6 egg whites
1 7/8 cup sugar
3 sticks (12 tablespoons) butter, softened, cut into smallish pieces
2 teaspoons vanilla

4 ounces semisweet chocolate, melted
1/4 cup seedless raspberry jam

Place the egg whites and sugar in a mixer bowl, and place the bowl on top of a pan of simmering water.  The bottom of the bowl should not touch the water.  Whisk constantly until the mixture reaches 150F-160F.  It's definitely easier with the thermometer. If you don't have one, it should take about 5-10 minutes, the mixture should be hot to the touch, and you shouldn't feel any sugar crystals, they should all be dissolved.

Remove from the heat, and attach the bowl to your stand mixer with the whisk attachment.  Beat on high until the mixture is completely cool, and the egg white have reached firm-stiff peaks.  I've read that this should take about 10 minutes, but it's taken me much much longer sometimes, so don't give up hope, keep beating.  Theoretically you can do this with a hand mixer too, but it will take even longer.

Switch to the paddle attachment on the mixer, and add the butter a few pieces at a time while beating on low-medium speed.  When all the butter has been added, increase to medium-high speed and beat a few more minutes.  Add the vanilla and beat another 30 seconds.  The frosting should be fluffy and not runny at all.  

Separate your buttercream:  place about 1/3 in one bowl (for the raspberry), and the remaining 2/3 in another bowl (for the chocolate). Beat the raspberry jam into the smaller portion of buttercream.  Beat the melted chocolate into the larger portion of buttercream.

Did Your Buttercream Break?

If your frosting curdles, do not despair, and whatever you do, do not throw it away!  It's fixable.  Whenever my buttercream "breaks," it's because the bowl gets too cold.  If that's the reason, just warm up the bowl (hold over a hot burner or steam or melt a few tablespoons in the microwave and add back to the curdled mess), and whip some more.  Magical chemistry ensues, and your buttercream will be beautiful and fluffy again soon.  If the bowl becomes too warm, the buttercream can also break; in this case, you'll need to chill it, bringing it back to room temperature (or slightly above).

Assembling the Cake

If you want to make frosting roses, you can make them out of buttercream - just up the recipe above by 1/2 or 1/3, and when separating the buttercream for the raspberry and chocolate, reserve some to color for the roses.  Or you can make a powdered sugar frosting, such as the vanilla frosting here. 

For information on how to pipe roses, see Wilton's tutorial.

The cake pictured is 2 8" layers, with the third layer tucked away in the freezer for later use. 

Be sure the cake is completely cool before frosting. I always chill my cakes to be safe, you don't want cake layers melting frosting and sliding every which way.  

Place one cake layer on a serving plate or a cake board, and spread the raspberry buttercream on top.  Top with the second cake layer, and cover the entire cake with the chocolate buttercream frosting.  

Pipe more frosting around the top and bottom edges of the cake if desired.  Top with frosting roses or sugared raspberries. Serve at room temperature.  Enjoy!