Divide the cake batter into 3 bowls. This is roughly about 400 g (14.1 oz) of batter per portion.
Add a drop or two of food coloring into each portion (yellow, pink and green). Mix the batter to create the pastel colored cake batters.
Dollop the batter into the prepared cake pan, while alternating colors. If you are using round cake pans, remember to divide the cake batter evenly between the pans - about 608 g (21.4 oz) batter per pan.
Swirl the colors in the pan, and make the surface smooth. Knock the pan on the counter/work surface 2 - 3 times to remove any air, and to even out the cake batter in the pan.
Bake the 9 x 13 inch pan in the preheated oven for 30 – 35 minutes (mine takes about 32 minutes). (See Recipe Notes for bake times for 8 inch or 9 inch pans).
Once the cake is baked, remove from the oven and let it cool down slightly. Turn the cake out onto a cooling rack, and let it cool down completely. The cake is now ready to be iced.
Evenly spread a layer of vanilla buttercream on top of the cake. Trim the edges to get clean straight lines.
Pipe a simple border with a small closed star tip. Sprinkle funfetti (optional) on the surface of the cake. The middle of the cake can be used to pipe a message OR can be kept clean.
For the Pastel Easter Cake
Divide the buttercream frosting into 3 portions. One portion should be less than the other two. Color the smaller portion with green food coloring. Color the other two with pink and yellow.
Apple a crumb coating to the top of the cake. Trim the edges of the cake, and crumb coat the sides as well.
Put each of the buttercream frosting into piping bags and cut openings. Use another piping bag to attach the piping tips (so that it'll be easier to change between the colors for each tip).
With a round tip, pipe two thin lines of the pink and yellow frostings along the side of the cake. Using an offset spatula smoothen the sides to create an ombre look.
Pipe some of the frosting on the top of the cake as well, creating random patterns. Using an offset spatula, spread the buttercream to create a swirled pattern, and to make it smooth.
Pipe a border along the cake with the rest of the pink and yellow buttercream.
Using the green buttercream frosting and tip #234, create grass patches on the surface of the cake. Using tip #18, create drop flowers with pink and yellow buttercream (optional). Decorate with Easter eggs and Easter bunny chocolates.
Place the cake on a cake serving platter and surround it with edible grass and more Easter eggs (optional).
Note on Baking Times2 x 8 inch pans = bake for 25 – 30 minutes (mine takes about 27 minutes).2 x 9 inch pans = bake for 20 – 25 minutes (mine takes about 22 minutes).