I made this Peppa and George Cake for my daughter's 4th birthday. She wanted a cake with both Peppa Pig and George.
I used two boxes of Pillsbury classic white cake mix and colored it pink (per her request lol). I greased my cake pan with Wilton's Cake Release (my favorite-the cakes always pop right out with ease). The top was a little too high coming out of the oven, and not very flat, so I took a dry dish towel and pressed the top down to make a flat surface.
I used Wilton's White Decorating Icing to frost and decorate the cake, along with Betty Crocker gel food coloring. For the base coat (the blue and green/sky and grass), I thinned the icing with a couple tablespoons of water. I didn't plan on making the grass at the bottom textured but was having trouble getting a clean line between the blue and green. I used a small flower tip to draw "blades" of grass. Once the blue was dry to the touch (about 20 minutes) I used a plain sheet of printer paper to gently smooth it.
To draw everything else, I poked the outline with a toothpick (that way if you mess up you can smear it a bit and hardly see the mistake). Then I outlined everything without thinning the icing at all as well as wrote the words. I let that dry for around an hour (10-20 minutes would probably do). To fill in the colors I added a dash of water and put the icing in the microwave for around 5 seconds (believe me that's all it needs!) and "flooded" the icing in. I was happy with all the coloring except the pink used on the pigs faces. I thinned that a little too much so it didn't set up as smooth as the rest.
It isn't bakery perfect but I'm pretty happy with it as I don't make cakes much, just for my kids birthdays. And my daughter loved it which is all that mattered anyway!