MELT 3/4 cup morsels in small, heavy saucepan over lowest possible heat. When morsels begin to melt, remove from heat; stir. Return to heat for a few seconds at a time, stirring until smooth. Cool to room temperature.
COMBINE flour, baking soda and salt in small bowl. Beat butter, granulated sugar, brown sugar, peppermint extract and vanilla extract in large mixer bowl until creamy. Add eggs, one at a time, beating well after each addition. Beat in melted chocolate. Gradually beat in flour mixture. Stir in remaining morsels and nuts. Drop dough by rounded tablespoon onto ungreased baking sheets.
BAKE in preheated 350° F. oven for 8 to 12 minutes or until sides are set but centers are still soft. Let stand for 2 minutes; remove to wire racks to cool completely.