1/4 c. butter
1 c. brown sugar
1 c. white sugar
3/4 c. sour cream

In heavy pan, melt butter, coating sides of pan. Add rest of ingredients. Cook over medium heat until sugar melts, then raise heat to 236 degrees. Add vanilla. Cool to 100 degrees. Beat until mixture holds its shape and loses its gloss. Add 1 cup nuts and spread immediately in a buttered pan.