I made peanut butter truffles with sugar, butter, evaporated milk, peanut butter, vanilla, and marshmallows. I have made this before with out any issues but this time when I made it and refrigerated it to scoop and dip in chocolate the filling was like dried out play dough. Had to toss it out. The only differences I can think of from making it this time to last time is a different range top and i added orange icing coloring. Could it have been the coloring or could I have burned the filling while boiling it on the range? Please let me know if you have any suggestions so I can avoid this fom happening again. Thank you.