For obvious reasons, this Purple Ombre Cake was the centerpiece of the entire 1000th Post Party last weekend. It stole the show. I kept it in the fridge while all the savory treats were being consumed so that it wouldn’t distract everyone from the awesome food they were eating. But that didn’t work. Inevitably, someone had to open the fridge to get a new bottle of champagne, and then the exclamations of amazement started.
I have to admit, I’m very proud of how this cake turned out. I wasn’t really sure how it would go. I knew I could do it, but I was worried I’d be frustrated with the decorating. As I have mentioned many times before, decorating a cake is not my strongest skill. Hubby even admitted later that when he saw the inspiration behind the cake, he didn’t think I had it in me. He honestly thought I was being over ambitious.
Don’t get me wrong, this is an ambitious cake. Four layers of cake, all a different gradient of purple, covered in roses, again piped in varying shades of purple. But believe me, with a little planning, and some practice, anyone can make this cake. I have a few tips on some things not to do, and some things to do when considering making this cake.
1. Don’t forget the sugar in two of the cake layers. This cake method is a bit different than most. Most cakes start with creaming butter and sugar. Not this one. It’s more like mixing biscuits. You add the butter to the dry ingredients before adding the liquid ingredients. So when your brain goes into autopilot and you mix the flour, baking powder, and salt in a bowl, don’t make the mistake I made and assume that’s all that goes in there! Add the sugar. FYI, I tried stirring in the sugar at the end and baking them because I hate wasting ingredients. The cake looked like cake when it came out of the oven. But it tasted… well, like the sugar was mixed in at the end. It was really sweet. And a little gummy.
So I had to re-bake two of the cake layers. Which means I have 18 egg yolks in my fridge right now. I see a lot of creme brulee in our future.
2. Don’t change your mind about the color of your frosting at the end. My original plan was to have the lightest shade of frosting be white. After piping the bottom two rows, I piped the first white rose and decided it was too big of a difference from the previous color. So I scraped that rose off, stirred in some purple food coloring and mixed up the lightest shade that you see in the finished cake. I’m sure you all think it looks fine, but I wish I had done that up front so I could have done the crumb coat in the lightest color. It annoyed the perfectionist in me that you could see specs of white peaking through between the roses.
3. Do mix up the cake batter in two batches. Trust me, you mixer can’t handle a double batch of that batter. To make your life easier, measure everything out for both batches at once. So when you put the flour in the bowl of your mixer, measure the same amount out and put it into another bowl. Then when it’s time to make the second batch, everything is measured and ready to go.
4. Do invest in a cake decorating turn table. Hubby is always on my case about the amount of baking gadgets I have. I have been eyeing one of these bad boys for quite some time but I didn’t know where I’d store it. I finally decided to just get one and figure it out later. I’m SO glad I did that. Applying the crumb coat took about 1/3 of the time that it takes without one and it helped when I was piping the roses too. Believe me, it’s worth the $18.
5. Do make this fruit passion curd. I don’t care if you’re intimidated by this cake, if you do nothing else, make the filling. Eat it with a spoon, on a graham cracker, or stuffed into a cupcake. It’s seriously delicious. Goya makes great frozen fruit purees in a variety of flavors. I want to make this curd in every possible flavor available (you can find the purees in the frozen food aisle near the other Hispanic foods). It’s SO simple and delicious.
6. Do as much ahead of time as you can. I feel like a broken record here, but the key with layer cakes not becoming too overwhelming is to break things up. I made the curd on Thursday night, baked the cakes on Friday, and made the frosting on Saturday. Then I just had to stack and decorate it before the party.
And last but not least, don’t be intimidated by the roses! They’re very simple to do and with a little practice, you’ll be a pro in no time. Just remember that to pipe roses, you start in the center and make one big swirl from the inside to the outside.
UPDATE: Click here for the Video Tutorial on How to Pipe a Rose
Hubby was shocked to watch me decorate the cake because it honestly took about 15 minutes total. The biggest pain was washing the tip between colors of frosting. And, to convince you guys even further, I’ve recorded a video of how to pipe roses! It needs a smidge of editing over the weekend, and I’m hoping to post it first thing Monday. So be sure to come back for that!
Such an impressive cake for any special occasion
Yield: Serves 16-20
For the Cake Layers
Double batch of White Cupcakes, baked into four 9-inch layers
Food coloring of your choice
For the Passion Fruit Curd
3/4 cup sugar
1/4 cup cornstarch
1 cup passion fruit nectar or puree - Look in the hispanic aisle in your grocery store - Goya makes all sorts of fruit purees
4 egg yolks
1 vanilla bean - split, seeds scraped
1 stick unsalted butter, cut into tablespoons
For the White Chocolate Buttercream
2 cups unsalted butter, softened
5 cups powdered sugar (or more, depending on desired consistency)
Pinch of salt
12 oz. good quality white chocolate, chopped (not white chocolate chips or candy melts!)
1/2 cup heavy whipping cream
1/2 tsp vanilla
Food coloring of your choice
For the Cake Layers
I recommend making the cake twice instead of doubling the recipe. While you're measuring out the ingredients for the cake, just measure out enough for the second batch at the same time so it's easier the second time around.
The first time through, leave one layer white. Add a few drops food coloring to the second layer prior to baking (I used 5 drops in my lightest layer).
When making the third and fourth layers, add a bit more food coloring to each layer such that you'll have gradually darker layers (I used 9 and 18 drops for my darker layers).
Allow all layers to cool completely.
For the Passion Fruit Curd
In a saucepan, whisk the sugar and cornstarch.
Whisk in the passion fruit nectar, egg yolks and vanilla seeds and cook over moderate heat, stirring constantly, until thick, 6 minutes.
Remove from the heat; whisk in the butter, 1 tablespoon at a time, until incorporated.
Scrape the filling into a glass bowl, press a sheet of plastic wrap on the surface and refrigerate until chilled, about 2 hours.
For the Frosting
Put the chopped white chocolate into a small bowl. Heat the chocolate in 30 second increments in the microwave set to 60% power. Stir after each increment, and continue to heat 30 seconds at a time, until the chocolate is melted and smooth. Set aside and allow to completely cool.
Once white chocolate has cooled, sift the salt and powdered sugar over the butter, in a large bowl. Cream the butter and sugar mixture together until light and fluffy, scraping the sides of the bowl as needed.
Measure the whipping cream into a cup, and stir in the vanilla extract.
With the mixer running on low speed, gradually pour the cream mixture the bowl.
Once the cream mixture has been incorporated into the frosting, fold on the melted (but cooled) white chocolate until incorporated.
Increase the mixer speed to medium-high, and beat frosting for an additional 3 minutes.
To Assemble the Cake
Once all of the cake layers have cooled, level each of the layers except the white layer.
Place a small amount of frosting on a cake board to stabilize the cake. Center the darkest layer on the cake board. Pipe a small ring around the edge of the cake layer. This will ensure the filling doesn't spill out between the layers.
Spoon a heaping 1/3 cup filling into center of cake and spread to the edges.
Stack the next lighter cake on top and continue the process until all layers are stacked and the white layer is on top.
Frost the cake with a crumb coat and chill in the fridge for at least an hour.
To Decorate the Cake
Place ~3/4 cup of frosting into two separate bowls (you'll have three bowls of frosting at this point, two with 3/4 cup, and one with the rest, which will be more than 3/4 cup).
The bowl with the most frosting will be your lightest color. Add food coloring to that bowl first until the desired color is reached. Color the other two bowls of frosting such that you have three shades of frosting.
Alternatively, leave all of the frosting one color.
Place the cake on a rotating cake stand. Starting at the bottom, pipe a row of roses along the cake using the darkest frosting color. You're going to pipe three rows of roses, so make sure they cover about 1/3 the height of the cake.
Continue with a second row of roses in the next lighter shade of frosting. Place the roses directly above the bottom layer.
Finish with one last row of roses in the lightest color. Next, decorate the top of the cake by piping a rose in the center of the top of the cake. Work your way around from there piping three circles of roses on the top of the cake.
If there are any large spaces between roses, you can pipe small stars into them to fill the space.