Rainow Cake Layers:
Note – this is a slightly-simplified layer cake recipe from ChelSweets.com – I highly recommend checking out her site if you haven’t before; she does incredible work!
3 1/4 c. all purpose flour
3 c. granulated sugar
2 1/2 t. baking powder
1 t. salt
1 cup unsalted butter (or 2 sticks) room temperature
2 t. vanilla extract
1 cup egg whites (about 7 eggs, or use carton egg whites to avoid wasting yolks!)
1 1/2 cups buttermilk, room temperature (or buttermilk powder with water is an option if you can’t find liquid buttermilk at your grocery store!)
1/8 cup (28 grams) vegetable oil
Red, orange, yellow, green, and purple gel colors (I used Americolor)
Flavors as desired – I used about a teaspoon each of raspberry flavoring (red/purple batter), orange extract (orange batter), lemon extract (yellow batter), and lime extract (green batter!)
Preheat oven to 350°F. Line four 7 inch pans (for taller layers) or three 8-inch cake pans with parchment rounds, and /or grease with non-stick or baker’s floured cooking spray.
Mix together all dry ingredients (flour, baking powder, sugar, and salt) in a stand mixer with a paddle until fully combined.
Mix chunks of room-temperature butter slowly into the dry mix, on a low speed. Continue to mix until no large chunks of butter remain, and the mixture becomes crumbly.
Pour in egg whites, and mix on low until just incorporated. Mix in the buttermilk in two installments, on a low speed. Add in oil, and mix at a low speed until fully incorporated. Scrape down the sides of the bowl with a spatula, then beat on medium speed for about 30 seconds.
Divide batter evenly between 5 bowls, and add colors and flavors as described above. Transfer into the prepared cake pans (I find a kitchen scale helpful for this part). This guarantees your layers will bake to be the same height. Swirl the colors together a bit with a small knife or offset spatula.
Bake for 35-37 minutes if using 8 inch pans, or 37-38 minutes for 7 inch cake pans (or until a toothpick comes out clean).
Allow cake layers to cool for 10-15 minutes on a wire cooling rack before removing from pans – it helps to run an offset spatula or knife around the perimeter of the pan first. Cool completely before frosting. Set in the fridge or freezer to accelerate the cooling process if desired.
Once the layers have fully cooled, the caramelized bits can be trimmed from the sides / top of the cake using a serrated knife if desired. Be sure the layers are completely cooled or chilled before trimming. If you try to trim the layers while they’re still warm, they will crumble apart.
Cream Cheese Buttercream Frosting:
8 oz (one package) cream cheese, softened
16 Tablespoons (two sticks) butter, softened
6-7 c powdered sugar
2-4 Tablespoons milk
Flavor extract of your choice – I used lemon extract and lime extract !
1/4 t. salt
Beat together softened cream cheese and butter; slowly add in powdered sugar alternating with milk until frosting reaches desired consistency. Add flavors and salt and beat until well combined.
– 1 8- or 10 -inch cardboard cake circle (I prefer Wilton’s center-punched circles) or an 8” acrylic cake disc (I started using these so I wouldn’t waste so many cake circles!)
– Large piping bag & tip – I use this set of reusable large bags & tips more than almost any of my others!
– 1 large bag + 1 box of Skittles – save the box!
– wood skewer (or cake dowel or straw)
– Cake leveler, cake turntable, large offset spatula, and pastry cutter/bench scraper – not all 100% necessary but incredibly helpful! (Here’s a link to the cake turntable I use)
Once your cakes are cool, level them (if needed/desired). This can be done with a cake leveler or a large serrated knife and a ruler. Place a smear of frosting on your cake circle (to keep the cake from sliding while you decorate it) and center your first cake layer in the center of the circle. Spread the layer with frosting.
Repeat the process with your remaining cake layers.
Now you’re ready to crumb-coat . If you’re unfamiliar with crumb-coating, it’s just what it sounds like – spreading a thin layer of frosting over the entire outside of the cake to keep crumbs out of your final layer.
Once your crumb coat has set (this takes about 5-10 minutes in the fridge), add your final layer of frosting and smooth. I like to use an offset spatula and bench scraper for this part. Once your cake is covered, place it into the fridge or freezer to set the frosting.
Candy Melt Drip:
– 8 oz white candy melts (I use the Wilton brand Bright White)
– 5 Tablespoons heavy whipping cream (the brand I usually use comes from Costco and is incredibly thick; do one test drip with 4 T if your cream is on the thin side!)
– few drops each Red, orange, yellow, green, and purple gel colors (I used Americolor)
This recipe is very similar to my white chocolate ganache recipe – you’re basically using candy melts instead of white chocolate to make a very similar drip ganache. Place heavy cream and candy melts in a microwave-safe bowl, and microwave on 50% power in 30-second intervals until smooth, stirring in between. Divide into 5 bowls and add your gel colors.
I usually find a squeeze bottle or piping bag work the best for this ganache, but I’ve used a spoon for similar drips before.
When your candy melt mix has cooled to a moderate temperature – it should feel slightly warm and still be fairly liquid – transfer each color to a squeeze bottle or piping or small ziplock bag. A spoon will work if you don’t have either of those; I’ve just found spoons to be a little bit more difficult to work with.
Slowly drizzle ganache around the upper edge of your cake – remember you have 5 colors, so space accordingly! Return cake to the fridge or freezer to set the drips.
Pipe frosting around the upper edge of your cake – this forms a rim to hold the pile of candy in place! I added some more candy melt mix to the frosting, but this is optional.
Open the box of Skittles and empty it, and then place your skewer into the open end of your Skittles box and close it – I cut a little of the edge of the box away to make room for the skewer. Push the skewer down into the cake, leaving the box on top of the cake at an angle. Add Skittles around the box to cover the top of the cake – and you’re done!