Hi, hope someone can help me. I purchased the Wilton royal icing mix box, where you just add the water for a flower decorating class I'm taking. I don't want to throw out the royal icing I made yesterday so want to use it for cookies I am decorating.

Someone in the class gave me a glaze icing recipe, which they tell me is perfect for decorating cookies. The recipe calls for the normal royal icing mix plus corn syrup and almond extract.

My question is can I use the already made Wilton royal icing mix and just add the ingredients I am missing which is corn syrup and almond extract to make the glaze icing?