Rocky Road Fudge

2-1/2 milk chocolate bars (Hershey) (8 oz. each) broken into pieces
1-12 oz. pkg. semi-sweet chocolate chips
1 c. (2 squares) butter (no substitute) cut into pieces
4 c. sugar
1-14 1/2 oz. can evaporated milk (1-2/3 cups)
2 1/2 c. miniature marshmallows
4 c. frozen miniature marshmallows
2 t. vanilla
1 lb. walnut halves
In large bowl, prepare broken milk chocolate bars, chocolate chips and butter pieces.  Set aside.
To freeze marshmallows, spread them on a large cookie sheet and freeze while cooking the following ingredients.
In large heavy saucepan, combine sugar, evaporated milk and 2 1/2 cups marshmallows.  Bring to boil over medium heat, stirring constantly.  Continue to cook and stir at a light but steady boil for 7 minutes.
Remove from heat and immediately pour over chocolate and butter.  With wooden spoon, stir until chocolate and butter are melted and mixture is well blended.  Continue to stir until candy loses some of its shine.
Stir in frozen marshmallows, vanilla and walnut halves and pour into buttered 9 x 13 pan AND buttered 8-inch square pan.  Refrigerate for at least 1 1/2 hours before cutting  Keep tightly covered and refrigerated until ready to serve.  Makes 5 pounds or more.
Note: fudge may be frozen successfully if wrapped in foil then stored in airtight plastic container.