In a large bowl, cream butter and sugar until light and fluffy, 5-7 minutes. Beat in eggs, 1 at a time. Beat in vinegar, food coloring and vanilla. In another bowl, whisk flour, cocoa, baking powder and salt; gradually beat into creamed mixture. Stir in chips. Refrigerate, covered, 1 hour or until firm., Preheat oven to 350°. Shape dough into 1-1/2-in. balls; roll in confectioners' sugar. Place 2 in. apart on parchment-lined baking sheets. Bake until tops are cracked and edges are set, 12-15 minutes. Cool on pans 5 minutes. Remove to wire racks to cool.