Wednesday, November 10, 2010

Pumpkin Spice Cake with Butterscotch Swiss Meringue Buttercream

One week before Halloween my adorable little nephew turned one year old. It was kind of a big deal for me. He is my only sister’s only child (thus far), and I absolutely love him to death. My sister threw a fun family party to celebrate, with a full compliment of party fixin’s - balloons, streamers, deviled eggs, and, of course, cake!

After we all met up in Reno a few months ago my sister gave me an assignment: come up with a recipe for my nephew’s first birthday cake. And I took it seriously. I didn’t want to let the little guy down! So I thought about flavors, researched recipes, and practiced a few test-runs to get things juuuuust right. And when I was confident in my creation, I handed the final, approved recipe over to my sis. Here are the results of her deft hand:

Way to decorate, sis!

Since the party was taking place so close to Halloween, my sister was thinking something with pumpkin. Pumpkin just so happens to be one of my favorite Fall flavors! I was looking forward to experimenting with recipes...just a tiny bit. There were just a few conditions. First, no chocolate. I guess the caffeine in cocoa isn’t great for the wee ones. Second, no lemon or banana cake. My sister isn’t a fan of lemon cake, and my mom is in the banana = ick camp. Such a shame on both counts, in my opinion. Finally, and most importantly, no cream cheese frosting. Sis doesn't do cream cheese frosting - it’s the tangy flavor. She hates it. She’s actually foregone eating cupcakes from her favorite local cupcakery because she unknowingly bought one with cream cheese frosting.

With these parameters in mind, I came up with a spiced-up pumpkin cake. Since the more traditional cream cheese frosting was off the table, I took inspiration from my favorite pumpkin cookies, and decided on a butterscotch buttercream. Pumpkin and butterscotch is a fantastic combination. Ever had it? You should. It’s yum. But butterscotch sauce is sweet. Super duper sweet. Husband says I’m just extra sensitive, but I thought my first butterscotch buttercream - a simple butter and powdered sugar mixture - was way too sweet. I didn’t see a way to reduce the sugar, so I just made some adjustments to help balance it. I added some acid. A little lemon juice really brightened up the flavor and gave the sweet somewhere to go. Also, I switched to a Swiss meringue buttercream. The light, fluffy texture did a good job of distributing the sweet on my palette, and was especially delicious paired with the warm spices of the cake.

The third and final test run I made a finished cake and brought it over to share with some lovely ladies I know. This cake here...

...was a big hit! Our host insisted on no leftovers, sent us home with every morsel of food, but when I asked her if she wanted the last slice of cake, she grinned sheepishly and nodded. With such approval I knew the recipe was ready for sisterly publication.

The day before the party my sister put her expert baking skills to action and whipped up my nephew’s birthday cake while I stood wringing my hands in the corner, prepared to die of shame should anything not turn out as expected. Even with a dozen other party provisions to prep, she made an awesome cake with an adorable smash cake of my nephew’s very own to match. She’s a rock star!

Whether for a special Fall occasion or just because cake is delicious, this cake is light and tender, very fragrant from the warm pumpkin spices, and so worth making! Sufficed to say I did not mind making - and subsequently eating - this cake three times.

Nephew's First Birthday Cake
(AKA: Pumpkin Spice Cake with Butterscotch Swiss Meringue Buttercream)

adapted from Martha Stewart

For the cake:
2 cups AP flour
1 tsp baking soda
1 tsp baking powder
1 tsp kosher salt
1 tsp ground cinnamon
1/2 tsp ground ginger
1/2 tsp ground nutmeg
1/4 tsp ground cloves
1/4 tsp ground allspice
1 cup sugar
1 cup dark brown sugar
1 cup (2 sticks) unsalted butter, melted and cooled
4 large eggs
1 can (15 ounces) pumpkin puree
1 tsp vanilla extract

  1. Preheat the oven to 350 degrees. Grease two 9-inch cake pans with baking spray, line the bottoms with parchment paper, then spray the parchment paper. 
  2. In a medium bowl, whisk together the flour, baking soda, baking powder, salt, cinnamon, ginger, nutmeg, cloves, and allspice. In a large bowl, whisk together the sugar, brown sugar, butter, eggs, pumpkin puree, and vanilla. Add the dry ingredients to the wet, and whisk until just incorporated and smooth. 
  3. Pour the batter evenly between the two prepared cake pans. Bake for 25-30 minutes, rotating the pans halfway through, until a cake tester (i.e. toothpick) inserted in the middle comes out clean. Transfer the cakes to a wire rack and cool completely. 

For the buttercream:
4 large egg whites
1 1/4 cup sugar
1 1/2 cups (3 sticks) unsalted butter, room temperature
2 tsp vanilla extract
pinch of sea salt
1TB lemon juice (or more to taste)
1/2 cup butterscotch sauce (see below)

(makes about 4 cups)

1/2 cup toasted pecans, chopped (to garnish the finished cake), optional

  1. In the bowl for your electric mixer (or a medium heatproof bowl if you’re using a hand mixer), combine the egg whites and sugar, and place the bowl over a small pot of gently simmering water. Whisking the mixture constantly until the sugar has fully dissolved, about 2-3 minutes. Rub a little between your fingers, and if there is no hint of a grainy texture, it’s done (or when it reaches 160 degrees in temperature). 
  2. Place the bowl in your mixer fitted with the whisk attachment, and set at high speed, beat the egg mixture until stiff peaks form. Continue beating until the eggs are fluffy and the mixture has cooled, about 5-6 minutes. Make sure the stiff peaks don’t become dry, you want them to stay glossy. 
  3. Switch to the paddle attachment and with the mixer on medium-low speed, add the butter 2 TB at a time, waiting until it is fully incorporated into the mixture before adding the next addition. If the buttercream begins in separate, turn the mixer up to medium-high speed and beat for a few minutes, until it is smooth again. Add the vanilla, salt, lemon juice, and butterscotch sauce (make sure it’s cool, you don’t want to melt your buttercream), and beat until incorporated. Again, if the mixture separates or thins out too much, beat on medium-high speed until it is light and fluffy again. Taste the buttercream and add more salt, lemon juice, or butterscotch if you think it’s needed. Reduce the mixer speed to low and beat for 2 minutes to eliminate any air bubbles. 
  4. Trim the tops of the cake layers so they are flat. Stack the first layer onto a cake plate and using a spatula, spread about 1/2 cup of buttercream in an even layer over the top. Place the second cake layer on top, making sure the two layers line up. Spread a very thin layer of the buttercream around the cake for a crumb layer. This will glue the crumbs to the cake, so they don't show through the light colored buttercream. Then apply a regular, thick layer of the buttercream, until the cake is evenly covered. Sprinkle the top with the toasted pecans and enjoy! 

For the butterscotch sauce:
1/2 cup (1 stick) unsalted butter
1/2 cup sugar
1/2 cup dark brown sugar
3/4 cup light corn syrup
1/2 tsp sea salt (or more to taste)
1/3 cup heavy cream
2 tsp vanilla

adapted from Martha Stewart
(makes about 1 1/2 cups)

  1. In a medium skillet, melt the butter over low heat. Add the sugar, brown sugar, corn syrup, and salt, and increase the heat to medium to bring the mixture to a boil. Let it cook for 2 minutes, then remove the pan from the heat and stir in the heavy cream and vanilla. Allow it to cool at room temperature. It will seem too thin at first, but don’t worry, it’ll thicken as it cools. 


  1. How fun... and yummy! I had a slice of pumpkin cake today with a cream cheese frosting. Tis the season!

  2. oh, you and the hand wringing. it was wonderful! everyone said so. Nate totally loved it. couldn't you tell?

  3. I'd totally pick that as my birthday cake! Though I have to admit I think cream cheese frosting totally "makes" a good pumpkin cake or cupcakes, I'm sure I could handle the butterscotch too :) Especially because the words "too sweet" just do not exist in my vocabulary!

  4. Cara, I'm with you. I'd prefer cream cheese frosting too, but with that off the table, I thought this worked quite well. ;)