1 c. real butter (no substitutes)
1 c. sugar
1/2 c. brown sugar
1 tsp. vanilla
1 pkg. milk chocolate chips
1 c. chopped walnuts, if desired

Mix butter, sugars and vanilla together in medium saucepan. Stir occasionally on medium heat until temperature reaches "hard crack" stage on candy thermometer or until a small amount tested in cold water hardens to consistency of toffee. Do not over cook! Remove from heat.

Pour mixture onto cookie sheet lined with aluminum foil. Allow mixture to partially solidify, then sprinkle with chocolate chips. When chips melt, spread over toffee. Dust with chopped walnuts, if desired. When entirely cooled, break into pieces and enjoy!