How can a burned sugar caramel icing be doubled? My icing recipe yields enough for a three layer cake. It covers between layers, sides,and top of cake. I would like to use 4 layers, so how would I do that? Ingredients are: white sugar, water, butter, milk, white Karo syrup, vanilla. Cook to soft ball stage. Cool to 110 degrees, then beat til spreading consistency. I've always been told not to double a candy recipe. This is essentially a candy recipe. What do you recommend? Don't want to risk ruining ingredients on such a time consuming recipe!
There is no reason a recipe like this can not be proportionally increased or decreased.  Just figure out how much you need and adjust from there. So, in your example, increase everything by 1/3. ...but I don't see how doubling poses a problem.