Watercolor Cake


Hello, hello!

Last Friday was Dad’s birthday, so naturally I had to make his favorite: vanilla chiffon cake with vanilla buttercream. That part was actually much easier than I expected, considering this is the first time that I’ve tried to tackle buttercream of any variety.

The hard part was actually figuring out how to decorate. According to Pinterest and the Internet, cakes for dads are either the generic grocery store kind (boring) or decorated with some amalgamation of beer, bacon, football, or shirt-and-tie combos, none of which really make me think, “Yup, that’s my Dad.” Seriously, though, cakes for dads are hard. (I am not looking forward to figuring out Father’s Day, but fortunately that’s still three whole months away.)


Fortunately, inspiration eventually struck thanks to my enormous archive of cake-decorating-techniques-to-try-someday. After watching probably every single tutorial on that exists on the Internet, I crossed my fingers, hoped for the best, and this dreamy blue sky watercolor layer cake came to be — the perfect touch of whimsy for any birthday spread, and 100% Dad-approved!

In case you want to create a more sunset-y or generally colorful effect, try mixing more than one watercolor “paint” color of frosting. Fortunately for us, unlike whipped cream, buttercream can pretty much be beaten within an inch of its life as you play around with the color, so feel free to experiment!

Just one note of caution: make sure to spread a thin layer of filling between your layers, or the whole thing will just slide around and almost topple over when you try to spackle on the frosting. I learned that the hard way and had to go back and remove excess filling after the third layer — don’t make the same mistake!


Hope you enjoy — Dad did!

Happy March at last,

Watercolor Cake

Buttercream recipe adapted from Serious Eats
Makes one 5-layer 6″ cake or one 2-layer 9″ cake


Chiffon Cake:
120 g (1 cup) all purpose flour
7 large eggs, separated into yolks and whites
4 tbs vegetable oil
4 tbs milk, any type
3 tbs + 7 tbs granulated sugar, stored separately from one another

Swiss Buttercream:
1/2 cup egg whites (4 large or 3 extra large eggs)
3/4 cups granulated sugar
1 tsp vanilla extract
1 cup (2 sticks) unsalted butter, cubed and softened at room temperature
1 tbs jam, jelly, or preserves (I used strawberry jam)
Food coloring (preferably gel, but liquid is fine for lighter colors)

Whipped Cream:
1/2 cup heavy or medium whipping cream
1 tbs powdered sugar (or more to taste)
Food coloring (also preferably gel, but again, liquid is fine for lighter colors)

Anything you’d like! I used a 3:1 mixture of strawberry jam and cream, but any jams, jellies, preserves, fruit curd, chocolate ganache, cookie butter, Nutella, and anything else that’s reasonably thick that you can think of is fair game!


Chiffon Cake:

  1. Preheat the oven to 350 °F and lightly grease your baking pans.
    Tip: I used five 6″ layer cake pans, but you should be able to divide the mixture into two 9″ round cake pans to a make a shorter, wider cake.
  2. Beat the 3 tbs of sugar into the egg yolks until well mixed, then beat in the vegetable oil and milk.
  3. Sift in the flour in 3 additions (add in 1/3 of the flour at a time), gently whisking in just until no visible dry clumps remain. Set the mixture aside.
    Tip: Especially after the first two additions, you will still see lumps in the batter after the dry, white clumps are mixed in. That’s okay! It’ll more or less smooth out after the third addition, and any lumps should be small enough not to make a difference once the cake is baked.
  4. Place the egg whites into the bowl of a stand or electric mixer and start whipping at a slow/medium speed. While the egg whites are still foamy, add the remaining 7 tbs of sugar in 3 additions about 20-30 seconds apart. After the third addition, whip the egg whites on high until the stiff peaks stage.
    Tip: When the egg whites are fully whipped, the mixture should be glossy and you should be able to lift the beaters out to leave a sharp standing peak behind that does not bend over.
  5. Add 1/3 of the whipped egg whites into the egg yolk mixture, gently folding in the whites until just until no large lumps remain.
  6. Pour the mixture into the remaining 2/3 of the whipped egg whites and gently fold together just until no streaks remain.
  7. Divide the batter into your cake pans and bake for 14-16 minutes for the 6″ cakes or 18-20 minutes for the 9″ cakes, or until an inserted toothpick comes out clean.
    Tip: This cake will puff up as it bakes, but shrink right back down to the original size once it cools, so go ahead and fill the pans to the brim if you can — don’t worry about leaving room at the top of the pan for the cake to expand!
  8. Set the cake layers aside to cool!
    Tip: After the layers are reasonably cooled, feel free to stack the layers, separating with parchment paper, for easier storage while you prepare the buttercream.

Swiss Buttercream:

  1. In a heatproof bowl, whisk together the egg whites and sugar.
  2. Set a steaming rack inside a small pot, then fill with water until the steaming rack is almost but not quite submerged. Bring the water to a boil and set the bowl of egg white mixture onto the rack. Whisk until the sugar has dissolved and the mixture no longer feels grainy.
  3. Keep whisking until the mixture registers 160 °F, then immediately remove from heat. Using a stand or electric mixer, beat the warm mixture until the meringue becomes cool and glossy.
  4. Beat in the vanilla and salt, then add butter one cube at a time (or about 1 tbs at a time, depending on how big your cubes are), beating well after each addition.
    Tip: The mixture may start to become lumpy as this happens. Don’t worry! Just keep beating until no little lumps of butter remain and the mixture is smooth.
  5. Beat in the jam, jelly, or preserves until the mixture is smooth.
    Tip: I used strawberry jam tinted with a little blue coloring, but forgot to strain out the strawberry seeds before I did. If you would like to, use seedless jelly (or heat up your jelly, then strain through a fine-mesh sieve) to avoid having little seeds in the finished frosting!
  6. Remove about 1/4 cup of the frosting and add pigment until it is about 1-1.5 times as dark as you will want the darkest parts of the watercolor to be. Beat thoroughly to mix.
    Tip: To create the bluish-periwinkle (the color of the letters) that I used on my cake, I used about 1/2 tsp of blue food coloring gel + about 5 drops of red food coloring, but get creative with your colors!
  7. If desired, also tint the base color. Set both colors of buttercream aside for assembly!

Whipped Cream:

  1. Pour cream and sugar into the bowl of a stand mixer.
  2. Whip the mixture, gradually increasing the speed from the lowest to the highest setting over the span of 1 minute then maintaining the mixer at the highest speed, until the whipped cream reaches the soft peaks stage. At this point, your beaters should leave a trail through the whipped cream, but any peaks that form when you lift them out should easily topple over.
  3. Add food coloring for pigment.
    Tip: To create the dark bluish-periwinkle that I used on my cake, I used somewhere between 1/2 and 1 tsp of blue food coloring gel + about 7-8 drops of red food coloring, but get creative with your colors!
  4. Keep whipping the cream until the color is fully incorporated and it reaches the stiff peaks stage.
    Tip: Whip just until you can achieve stiff peaks when you lift out the beaters. If you accidentally over-whip your cream as you are adjusting the color, add a little more unwhipped cream and gently incorporate with a whisk until the cream smoothes out again.
  5. Set aside for assembly!


  1. Place your first layer of cake in the center of your serving plate or cake holder.
  2. Spread a thin layer of your filling in the center of your cake, stopping about 1/4″ to 1/2″ inch before you reach the edge of the layer.
  3. Gently place the next layer of cake on top of the first layer, and repeat for all remaining layers.
    Tip: After stacking each layer, make sure that your cake is level, centered, and properly balanced. It is much easier to keep everything even and balanced to begin with than to try to fix a lopsided cake later after frosting!
  4. If you have one, place your plate onto a rotating cake stand for frosting. Using your base color of buttercream and an offset spatula, spread on a crumb coat by spreading a thin layer of buttercream all over the cake to seal in any gaps and stray crumbs.
  5. Place a generous dollop of buttercream in the center of the top layer, and gently smooth out with the flat edge of the offset spatula. Continue smoothing out, rotating the plate as you go, allowing the frosting to spread until it hangs over the edges of the cake.
  6. Smooth any overhanging frosting downward using your spatula to evenly cover the sides of the cake. If you don’t have enough frosting, add more to the center of the top layer, repeating the smoothing process outward and downward.
  7. To flatten out the top, place the spatula horizontally against the top surface of the cake near one edge such that the side of the spatula makes a 45 degree angle with the top of the cake . Using a long, even stroke, pull the spatula toward the other edge. Repeat at different points along the top surface of the cake until the top surface is smoothed out.
  8. To create a smooth, even edge, hold the edge of the spatula vertically at a 60 degree angle along the side of the cake, and rotate the cake away from the angle. Apply a constant, light pressure with the spatula as you turn, and stop once the frosting is smoothed out.
    Tip: To clean up any stray frosting on your plate, wipe down the surface of the plate with a wet paper towel.
  9. To create the watercolor effect, randomly scatter dime-sized spots of tinted buttercream at varying spots along the side of the cake. Place the spatula vertically against the side of the cake just as you did to smooth out the frosting on the sides of the cake and rotate the cake on its stand.
    Tip: By varying the angle and pressure on the spatula, you can control how much base vs. accent color you see. With more pressure and/or a larger (closer to 90 degree) angle, there will be more base color; with less pressure and/or a smaller (closer to 0 degree) angle, there will be more accent color.
    Also, if you don’t plan on adding any text, consider also adding watercolor to the top surface, using the same technique to add splotches of color and then smooth them out.
  10. Using a piping bag and large tip, decorate the edges with spirals of whipped cream.
    Tip: I used a Wilton 1M tip for the classic frilly edge, but feel free to use whatever you’d like!
  11. Load the remaining accent colored frosting into a sandwich bag, then cut a small hole in one corner. Pipe out any text as desired.
  12. Slice and enjoy!




2 thoughts on “Watercolor Cake

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s