Place sugar in a cast iron skillet. Stirring constantly with a wooden spoon, cook the sugar until it is completely melted and has turned an amber brown, about 8- 10 minutes. If the sugar is lumpy, break up the lumps with the wooden spoon.
Turn off the heat and let it cool. Pour into a glass jar and allow to cool completely overnight. This makes about 1 cup of syrup.
Cake
Preheat the oven to 350 deg. Prepare 2, 9 in round cake pans by greasing them with margarine and a thin layer of flour. Place a parchment paper circle at the bottom and grease the parchment.
Beat sugar, margarine, and egg yolks until fluffy. Add water, vanilla, & sifted flour, salt and baking powder. Beat well & add in ½ cup of the sugar syrup. The batter will be slightly thick. Gently fold in egg whites.
Pour evenly into 2, 9 inch pans and bake for 25 min, rotating after 12 min.
Icing
Melt sugar in a medium saucepan w/ margarine, cream & peanut butter. Bring to a boil and cook until thick (about 10 minutes).
Add powdered sugar and mix together. Let cool for 15 minutes or else the cake will break.
Building the Cake
Let the cakes cool completely before building. Level both cakes (I usually just take the highest part of the dome off). Place one cake onto your cake plate. Dab a little (about a tablespoon) of burnt sugar syrup onto each of the cakes.
Spread a thinish layer of the icing on top of the cake on the cake plate. Top with the second cake and spread with the rest of the icing. Do this a little at a time, the icing should be about ⅛ - ¼ in thick all the way around so it just starts to drip over the sides.
Let it sit uncovered for about 2 hrs. Wrap loosely with plastic wrap or cake plate lid and let sit in the fridge or a cool, dry place overnight.
Notes
Fiji water is fluorinated, you can also find it in the baby section.
The cake does not always require all of the icing.
To make candy from the extra icing, place the pan back on medium low heat and cook for about 10 more minutes. It will get runny and harden as it cools. Pour icing onto parchment and let cool. The final candy will be the texture of hard toffee.