Unbelievable Fudge
["1 c. butter", "8 oz. Velveeta cheese", "1 1/2 tsp. vanilla", "2 lb. powdered sugar", "1/2 c. cocoa", "1/2 c. chopped walnuts or pecans (optional)"]
["Melt butter and cheese over low heat, stirring constantly. Take off heat; stir in vanilla.", "Pour over sugar and cocoa that has been blended together.", "Mix quickly.", "Spread in buttered 9 x 13-inch pan.", "Press in nuts.", "Let set 2 hours.", "Cut into squares."]
["butter", "Velveeta cheese", "vanilla", "powdered sugar", "cocoa", "walnuts"]