Blend together the softened butter and the brown sugar on medium speed until creamy. Add vanilla and mix well. Gradually add flour and condensed milk until blended. Stir in chocolate morsels and chopped nuts. The nuts make this mixture more solid. You can leave the nuts out if preferred or if you have to (allergies) but the 'cookie dough' will be more sticky. Paula uses chopped pecans. I used chopped macadamia nuts (heaven), chopped walnuts (good) and without nuts.
Using floured hands, (I use two spoons), scoop out cookie dough and shape into balls. Don't be tempted to make these too big! You can just plop them on the cookie sheet if you like a more free-form candy. Place them on cookie sheets (easiest to remove if you put down a layer of parchment paper) Chill the cookie dough balls about 2 hours until firm.
Melt the chocolate and shortening over low heat and stir to blend. (don't let it scorch!)
Dip the cookie dough balls in the chcolate one at a time to coat. Place each one back on the cookie sheet and chill to harden.