The batter actually coloured up really nicely with only the tiniest drop. I thought you might have to add quite alot, and was worried about how that would affect the taste of the cake but it wasn't a problem. Now the layering of the cake cases before they go into the oven is what takes the time, I didn't time myself but I'm pretty sure I spent at least an hour doing this. Adding two teaspoons of each colour, patting it down to an even layer and then repeating with the remaining four colours. I'm pretty sure you could just put blobs of different colours randomly in the cases and it would still come out like a rainbow but I wanted to go for the straight lines look. Here are the cakes fresh out of the oven:
It was pretty late by this point so I popped them safely in my cupcake courier to keep them fresh and went to bed. This morning I woke up and whipped up some vanilla buttercream courtesy of Hummingbird Bakery's cookbook. I was considering making rainbow frosting but I didn't have enough time with all my other tea party preparations!
Byron thought they should have rainbow sprinkles on too but I liked the contrast of the white against all that colour and just having a little smarties egg on top but I did a few sprinked ones to keep him happy:
Rainbow Cupcakes:
Makes 24
From Martha Stewart's Cupcakes
3 1/4 cups cake flour, sifted
1 1/2 tbsp baking powder
1/4 tsp salt
1 tbsp pure vanilla extract
1 cup plus 2 tbsp semi-skimmed milk
1/2 cup plus 6 tbsp unsalted butter
1 3/4 cups caster sugar
5 large egg whites, room temperature
Gel paste in various colours: yellow, red, purple, blue, green
Preheat oven to 180 degrees C.
Sift together cake flour, baking powder and salt. Stir vanilla into milk.
With an electric mixer on medium-high speed, cream butter until smooth. Gradually add sugar, beating until pale and fluffy. Reduce speed to low.
Add flour mixture in three batches, alternating with two additions of milk, and beating until just combined after each.
In another bowl, with electric mixer on high speed, whisk the egg whites until stiff peaks form (do not overmix). Fold one third of the egg whites into batter to lighten, gently fold in remaining whites in two batches.
Divide batter evenly among 5 bowls and use a few drops of gel colour in each bowl until you reach the desired colour. Layer each colour, 2 tsp at a time, in cupcake cases. Repeat until all 5 colours have been used. Do not fill cases more than 3/4 full. Firmly tap the tins once on countertop to release any air bubbles.
Bake, rotating tins halfway through, until a cake tester inserted in centers comes out clean - about 18 to 20 minutes. Let cupcakes cool in tins for 10 minutes and then transfer to wire racks to cool completely.
Vanilla Frosting:
Makes enough to frost the above
From The Hummingbird Bakery Cookbook
500g icing sugar, sifted
160g unsalted butter, at room temperature
50ml whole milk
a couple of drops of vanilla extract
Add half the icing sugar and half the butter to a freestanding electric mixer with a paddle attachment. Beat on medium-slow speed until the mixture comes together and is well mixed. Add the remaining butter and sugar and beat again until it is all combined.
Combine the milk and vanilla extract in a separate bowl, then add to the butter mixture a couple of tablespoons at a time. Once all the milk has been incorporated, turn the mixer up to high speed. Continue beating until the frosting is light and fluffy, at least 5 minutes. The longer the frosting is beaten, the fluffier and lighter it becomes.
Pipe frosting onto cupcakes using a closed star tip. Decorate with rainbow sprinkles or smarties mini eggs.
Here is our afternoon tea table...sandwiches, crisps, scones and cupcakes, and some cupcake bunting for decoration - it can't get better than that!
