Sweet Potato Cake

Sweet Potato Cake

Every month, the Cake Slice Bakers take a recipe from the year’s chosen cookbook (currently Sky High : Irresistible Triple Layer Cakes, by Huntsman & Wynne) and bake it up for your delectation.

This month’s offering heads into some definitely unknown territory – the Sweet Potato Cake is three layers of spiced sweet potato cake, filled with orange cream cheese icing and frosted with Chocolate cream cheese icing. Sweet potatoes, orange, and chocolate? I was definitely curious enough about it to give it a whirl pretty much as written…

I did have some quibbles with the way the recipe was written – when someone tells me to “bake 12 ounces of sweet potatoes, peel, puree, and set aside one cup for later”, I expect that the first time the recipe calls for sweet potatoes I’m using the part that didn’t get set aside, which is what I did. However, ‘later’ never came – after I’d baked the cakes and was making sure I had everything ready to put the frosting together, I noticed that I still had a forlorn-looking cup of sweet potato puree sitting on the counter.

“Hmm,” says I. I re-read the recipe. No further sweet potato usage. Checked it twice, even. Nope.

The part I used was about the same quantity, thankfully, but it could have been something of a wreck, there.

(I do wonder if the funny blotches were because of not enough puree, or because I didn’t fold in the egg whites thoroughly enough.)

Why the weird white blotches?

Why the weird white blotches?

Managed to get my cream cheese out to come to room temperature hours ago (go me!), but went to put together the frosting and realized that I’d not done the butter. Drat. I’ve been having bad luck lately with microwave defrosting (it worked for a while, but now there seem to be hot spots and I get melty bits), so I was thinking about mashing it up for a bit to warm it (It was already 10pm, and I want to sleep sometime, hence the not naturally warming it) when I remembered a trick I’d learned from someone years ago and forgotten ’til this moment. Which is why I wrote up most of this post with a stick of butter tucked up against my nice warm skin :) (This is not a trick to do with food you intend to sell, obviously, but as long as everything stays in its wrapper I feel that friends and fellow volunteers are more than fair game for body-warmed-butter.)

Butter and cream cheese played nicely together, but when I added the (melted, now room temperature) chocolate, instead of melding nicely it froze up solid into little chunks. So we shall pretend that we meant it that way, neh? It’s so pretty with its little flecks, is it not?

The icing, already sort of soft, did not get any firmer when adding 2 TB .25 tsp worth of liquid to it, oh no. Another cup of powdered sugar and I could be fairly certain that it wouldn’t explode its little buttercream boundaries and go all over everywhere, but barely.

The first layer came out beautifully! It was so pretty I thought about just making three cakes, but decided to continue.

The first layer - so pretty!  That's orange frosting in the middle.

The first layer - so pretty! That's orange frosting in the middle

I toyed with the idea of not frosting the sides, letting the natural beauty of my little stars shine through, but remember that soft icing? As soon as I put the second layer on, it squished something fierce.

Thinking ahead (forecasting, provenance of the higher apes, ook), I refrigerated the cake and the icing so that the third layer would not squish out all of the frosting when I placed it on the other two. Success! One more layer of icing, another stint in the fridge, and then the final decoration. (I was sad that I hadn’t saved more orange icing, as it would have made a nice top layer. Good to remember for next time.)

Finishing off the cake with the chocolate frosting

Finishing off the cake with the chocolate frosting

Taste-wise?  So far I’ve only had the frosting – the cake itself is going to a volunteer appreciation dinner tomorrow night (it barely, barely fit into my cake carrier – whew!).  The frosting is really sweet, and the combination of really sweet cream cheese and unsweetened chocolate just clashes, to my mind.  The orange was tasty, but again, so achingly sweet.  Shall report back when I find out how it all tastes together!

Recipe:

Sweet Potato Cake
from Sky High: Irresistible Triple-Layer Cakes

Cake:
2 medium or 1 large sweet potato (12 ounces)
3 cups of cake flour**
3 teaspoons of baking powder
1 and 1/2 teaspoons of ground cinnamon
3/4 teaspoon of ground nutmeg
1/4 teaspoon of cloves
5 eggs, separated
2 and 1/4 cups of sugar
1 stick plus 2 tablespoons of butter, at room temperature
1 and 1/2 teaspoons of vanilla
1 and 1/4 cups of milk

(**The recipe calls for cake flour and if you only have all-purpose flour on hand, you can substitute 3/4 cup (105 grams) all purpose flour plus 2 tablespoons (30 grams) cornstarch.)

(*If fresh sweet potato is not available where you live you may use canned sweet potato, yams, and pumpkin puree)

Makes a 9-inch triple layer cake, serves 16-20 people

1. Preheat the oven to 400F degrees. Prick the sweet potatoes in 2-3 places, place on a small baking dish and bake for 1 hour or until the potatoes are very soft. Remove from the oven and cool slightly.

2. Reduce the oven temperature to 350F degrees. Butter the bottoms and the sides of the pans and line with parchment paper. Butter the parchment paper also.

3. When the sweet potatoes are cool peel off the skin and remove any dark spots. Cut the potatoes into chunks and puree in a food processors. Puree until smooth. Measure out one cup of potato puree and set aside [to use in just a minute :)].

4. Sift the flour, baking powder, cinnamon, nutmeg, and ground cloves. Set aside.

5. In the bowl of electric mixer add the egg whites and attach whip attachment. Beat on medium speed until egg whites are frothy. raise the speed to high and gradually beat in 1/4 cup of sugar. Continue to beat until the egg whites are moderately stiff.

6. In another large bowl with the paddle attachment, combine the sweet potato, butter, vanilla, and remaining sugar. Beat until light and fluffy. Add the egg yolks one at a time. Make sure to scrape the sides of the bowl after each egg yolk is added. With the mixer on low speed, add the dry ingredients and milk in alternately in 2-3 additions. making sure to begin and end with the dry ingredients.

7. With a large spatula, fold in one fourth of the egg whites into the batter to lighten. Then fold in the remaining egg whites until no streaks remain. Making sure to not over mix or this will deflate the batter. Divide the batter among of the three pans.

8. Bake for 25-30 minutes or until a cake tester comes out clean. Let the cake layers cool in the pan for 10 minutes. Then turn out the cake layers onto a wire rack and cool completely at least 1 hour.

9. To assemble the cake, place one layer flat side up on to a cake stand. With a pastry bag fitted with a 1/2 inch round tip and filled with chocolate cream cheese icing, pipe border around the edge of the cake. Fill the center with the orange cream filling smoothing it to the edge of the border. Place the second layer on top and repeat the process.Place the third layer on top and use all the chocolate cream cheese frosting to cover the top and sides of the cake.

Chocolate Cream Frosting:
makes 3 cups
10 ounces cream cheese*** at room temperature
1 stick of butter at room temperature
16 ounces of powdered sugar; sifted
1 and 1/2 ounces of unsweetened chocolate melted and slightly cooled

(***1 cup of cream cheese maybe substituted with 1 cup pureed cottage cheese OR 1 cup plain yogurt, strained overnight in a cheesecloth OR equal amounts of neufatel cheese)

1. In a large mixing bowl, beat together the cream cheese and butter until fluffy. Slowly add the powdered sugar to cream cheese butter mixture. Making sure to scrape down the sides the sides of the bowl. Then beat until light fluffy 2-3 minutes.

2. Measure out 1 cup of frosting and set aside.

3. Add the melted chocolate to the remaining icing in the bowl and beat until well combined. If your chocolate seizes all up and therefore your icing isn’t chocolate-colored, add some cocoa powder, about a tablespoon.

Orange Cream Filling:
1 cup of reserved cream cheese icing from above.
2 tablespoons of frozen orange juice concentrate, thawed
1/4 teaspoon of orange extract

1. Stir together all the ingredients until well mixed.
If it’s a runny, gloppy mess, add more powdered sugar until it isn’t.