Rainbow cake

Last week, in honor of Parshat Noach, I baked a rainbow cake.  My friend Heather (you remember the one with the corrupting influence?) introduced me to the idea from this blog.  She made the cake when we visited them last summer for a birthday celebration for her daughter and Peach (who were born three days apart six years ago).  Once the batter was made and dyed, here is how she layered it in the baking tins:

And here is the big moment when she cut the first slice:

I did the minor decorating job on Heather’s cake, piping some white flower-shaped tufts of “cloud” with the icing and the scalloped border.  The main difference between Heather’s cake and mine is that hers was entirely store-bought and mine was entirely homemade.  What I discovered is that a compromise is good for this cake.  I recommend the finest store-bought ingredients for the cake (Heather used the whitest mix she could find, and Wilton gel food colors), and a good homemade buttercream frosting for the outer decoration.  Cake mixes have a denser batter and hold the dye better; my homemade batter was too slushy and the result was more of a tie-dyed cake than a rainbow one.  And store-bought frosting (in the cardboard can) is too soft to hold any kind of shape when spread or piped on a cake. Here are a couple of shots of my recent decorating job.  (Sorry the sloppy, tie-dyed effect couldn’t be displayed; it was cut on Shabbat.)

The cake as a whole is almost sickeningly sweet, and barely looks like food.  But if you want to make friends and establish influence with members of the child set, this is the way to go.

For those who are looking for a good buttercream frosting recipe, here is the one I use, based on the recipe I was given at the Wilton basic cake decorating course:

150 g margarine or salted butter, fresh out of the refrigerator

2 tablespoons water (or milk or whipping cream)

1 teaspoon flavoring (vanilla, orange, rum, etc.)

1 tablespoon meringue powder (Wilton makes this, and it can be purchased online or in a craft store like A.C. Moore or Michael’s)

560 g powdered (confectioner’s) sugar (1¼ lbs) (do NOT use superfine sugar; the frosting needs the cornstarch to give it consistency and bind)

Pulse margarine in food processor.  Add liquids and meringue powder and pulse together until blended.  Add sugar about 100 g (or 1 cup) at a time, pulsing in between to combine.  I recommend using a spatula to scrape the sides and bottom of the food processor bowl and pulsing a little more to be sure to incorporate all of the frosting.

This method makes frosting with a stiff consistency, suitable for making roses.  For medium consistency (other flowers) add an additional 1-2 teaspoons water or milk and blend thoroughly.  For spreading (also vines, leaves, and lettering), add an additional 2-3 teaspoons water or milk and blend thoroughly.

If I know I’m only making frosting to spread on a cake, I simply reduce the amount of powdered sugar I add to the food processor.  Test frosting with a spreading knife between additions, adding the last 200 g of powdered sugar gradually.