Beat butter & sugar; add vanilla & egg, blending well. In a separate bowl mix together dry ingredients. Add to buuter mixture alternately with milk, blending well. Refrigerate dough about an hour or until firm enough to handle. (Dough will be a liitle soft.) Lightly grease cookie sheet. Heat oven to 350 degrees F. Shape small portion of the dough around unwrapped peppermint patties, completely covering candy. Place on prepared cookie sheet; flatten slightly & crimp with tines of a fork around the edges, if desired. Bake at 10-12 minutes or until set. Cool 1 minute, remove from cookie sheet to wire rack. Cool completely.