In a large bowl, cream the butter and brown sugar until light and fluffy. Beat in vanilla. Gradually add flour, alternately with the condensed milk, beating well after each addition. Stir in the mini chocolate chips and chopped walnuts. Shape into 1 inch balls. Place on waxed paper lined baking sheets. Loosely cover and refrigerate for 1 to 2 hours or until firm.
In a microwave safe bowl, melt candy coating. Stir until smooth. Dip balls in coating, allowing excess to drip off. Place on waxed paper lined baking sheets. Refrigerate until firm, about 15 minutes. If desired, re-melt remaining candy coating and drizzle over tops of truffles. (Or, you can buy a different color of coating to drizzle. Easiest way to drizzle, pour melted chocolate into a ziploc bag, close the bag and cut a tiny corner of the bag and begin drizzling.
Store in an airtight container in the refrigerator. (Since I only make these in the winter time for Christmas, I store them out on my back porch in the containers rather than to take up my refrigerator space. Works great! They will keep for a couple of months as long as kept cold.)
Makes about 5-1/2 dozen.
*Note: if melted chocolate begins to thicken during coating, add a teaspoon or so of Crisco and mix well. It will thin it out a little better. Do not use butter... it won't work.