To make caramel boil the sweetened condensed milk, still canned, in a pan with water for a really long time. I'm not 100% sure about the time needed to reach caramel. Just wing it or just buy some caramel from the store.
- Preheat oven at 350 degrees and bake cake according to recipe. Spray or butter/flour cake pans. Place 3/4 of the batter in a metal or oven safe bowl and the last quarter of batter in a small cake pan. Remove when cakes are finished. The smaller one will finish first. Cool in pans on racks.
- Meanwhile, in a small sauce pan over medium low heat. Cook evaporated milk, egg yolks, sugar until thick enough to coat the back of a spoon and doesn't run when you swipe your finger across the spoon. Remove from heat add coconut and vanilla. Allow to cool.
- Once the cakes are cooled flip them out and gently cut shapes out for the head, legs, arms, and tail. On the bowl shaped cake carefully slice the bottom off and then flip the cake over. Now that you have the bottom removed use a spoon and gently scrape out the middle to create a bowl leaving 3/4 inch wall all around the bowl. Sprinkle peanuts and cover with caramel. Scoop out ice cream and fill the cake. Repeat one more layer of peanuts and caramel. Using butter cream in a piping bag, or zip lock bag, seal the bottom of the cake to the top. Gently flip over on to your serving platter. Freeze until hardened.
- Remove cake from freezer and use your left over cake crumbs to create a dome shape for your shell. Cover the "shell" with coconut icing. Then using butter cream "glue" the head, tail, legs, and arms to the shell. Add green food coloring to your buttercream for your turtle's skin. Pipe the colored butter cream to the turtle's head, tail, legs and arms until completely covered. Use a small round tip to draw the scutes on the turtle's shell. Place M&M's on the head for the eyeballs and if you'd like to make a Red-ear slider use red M&M's to make the ears.
- Place the cake in the freezer until completely hardened. Make up to one day before you use.