I was also looking for the Wisconsin version of cashew crunch that lists those three ingredients...Here is what I found which sounds like it might be correct:

AMISH CASHEW CRUNCH

1 cup butter
1 cup sugar
2 cups cashews

In a heavy pan cook and stir the butter and sugar until it looks liken vanilla pudding. Add the cashews and cook until it starts to turn golden brown like peanut brittle. Pour out on lightly greased cookie sheets. Cool. Break up in pieces. Store in airtight container.