Put 1/2 jar of nuts in 9x13 pan. Melt butter and peanut butter chips in microwave. Add condensed milk and microwave 1 to 2 min. DO NOT BOIL. Fold in marshmallows and spoon/spread over nuts in the pan. Add the remainder of the nuts evenly over the top. Gently push down nuts. (your hand inside a small plastic bag works well to push them down) Chill. Cut into squares.