16 oz Semi-sweet chocolate chips
2/3 c Sweetened condensed milk
1 ts Vanilla extract
1 c Walnuts; coarsely chopped

In top of double boiler, placed over simmering water, melt chocolate. Stir in Sweetened condensed Milk. Remove from heat. Stir in remaining ingredients. Turn into greased, waxed paper OR metal foil-lined and greased again 8x8" pan. Bake in 375 degree F oven until toothpick inserted in center comes out clean, about 25 minutes. Turn out of pan onto cake rack. Peel off paper. Cool. With sharp knife cut into 2" squares.