Butter an 8 inch square pan. Spread the walnuts on a baking sheet and bake in a preheated 350 F oven until they are light brown and fragrant, about 10 minutes, watching carefully so they do not burn. Let cool for at least 10 minutes. Meanwhile, chop the chocolate into small pieces. Cut the marshmallows into quarters, using kitchen shears dipped in hot water. Melt both chocolates and the butter in the top of a double boiler over gently simmering water. Off the heat, stir in the marshmallows, nuts and vanilla, then spread in the prepared pan. When firm, cut into 1.5 inch squares. Store in air tight containers in a cool, dry place for up to a week.{$7e}(Original recipe for 12)
