I had made this once before by accident when I was younger. I had set a mixture of evaporated milk and sweetened condensed milk in the freezer when I wanted to save it for a cheesecake filling. I forgot about it, and when I took it out, it sort of hit me to taste it. Of course, the taste (and texture) was exactly like something you'd buy at the store. I don't know if this exact recipe already exists, but if it does, there's probably a better version.