Reid’s daycare teacher decided to celebrate the birthdays of all of the kids whose birthdays fall in the summer tomorrow. I immediately volunteered to bake the cake that they would share. I’ve been looking for an opportunity to try my hand at a rainbow cake, like the one Amy at Muddy Boots made. I doubt I’d enjoy the additional stress in the midst of planning for a real party but without the rest, I was keen. I started the cakes at 6 and finished by 11:25. I’m so wired from the sugar – mmmm, marshmallow fondant – and I’ve got a second wind, that I decided to write down what I did.
I followed Amy’s directions for the rainbow cake -basically, I added gel icing colouring to white cake mixes – and also followed her directions for marshmallow fondant. Her instruction to grease your hands with Crisco was critical to success!
Adding the food colouring to the cake batter was a bit like making playdough. I loved the vivid colours.

Just look at them! You know the cakes are going to be amazing.

In order to avoid baking 6 cakes – 2 at a time in my little oven -I put two colours in each pan. Another time, I think I’ll try 6 cakes.

I need to learn how to bake cakes with flat tops. I had to cut the rounded parts off of the first two cakes. Of course, this meant that I had to try the cakes, just in case.

I melted a small bag of marshmallows in the microwave in only 1 minute and added about half of the 1 kilogram bag of icing sugar before remembering to add the 2 tablespoons of water called for in the recipe.

The water kneaded in easily and I added probably 3 tablespoons when all was said and done.

Amy mentioned chilling the fondant overnight but I didn’t have the time and it rolled like a charm still warm.

I measure against theh top of my cake-taker to see the size of marshmallow fondant I would need and then draped it over the cake. Marshmallow fondant is much more forgiving of irregularities in the stacked cakes than regular icing. If only I could figure out how to make cream cheese-flavoured fondant, I’d switch to it entirely.

I used some more icing gel to colour more marshamallow fondant to decorate the top of the cake. Reid has been very interested in rainbows lately, thanks in part to They Might Be Giants’ ROY G BIV, a song about the colours in a rainbow. I couldn’t manage indigo. She’ll have to tell the kids its ROY G BV instead.

And here is the final product. Ta da! (If I can get a teacher to take a picture of the cake once it’s cut, I’ll post it, too.)

Edited to add: I asked Reid’s teacher to take a pic of the cake once it was cut since I couldn’t see the inside. She sent this piece home with Reid. You can’t taste the food colouring.
