Grease and line with waxed paper, then grease again a 15 x 10 x 1 inch pan (jelly roll). Melt in double boiler:

1 sm. pkg. chocolate chips
2 tbsp. shortening

Remove from heat and add 1 can sweetened condensed milk, 1 teaspoon vanilla and 1 cup flour. Spread in greased, lined pan. Bake for 10 minutes at 325 degrees.

Make filling while cookie part bakes. Melt in double boiler 1 small package butterscotch chips and 2 tablespoons butter.

Spread out towel, sift powdered sugar all over it. Remove cookie from oven and turn immediately onto sugared towel. Spread immediately with the butterscotch filling.

Sprinkle with nuts. Starting with 15 inch side, roll up immediately, as tightly as you can. Wrap roll tightly in waxed paper. Chill 6 hours or overnight. Slice.