Preheat oven to 325 degrees F. In a medium mixing bowl, stir together the flour and brown sugar. Using a pastry cutter, cut in the butter until mixture resembles fine crumbs and starts to cling. Stir in pecans and vanilla. Form the mixture into a ball and knead until smooth.
On an ungreased cookie sheet, pat or roll the dough into an 8-inch circle. Using your fingers, press to make a scalloped edge. Using fluted pastry wheel, cut circle into 16 wedges, leaving circle shape intact.
Bake in a 325 degree F oven for 25 to 30 minutes or until bottom starts to brown and center is set. Cut circle into wedges again while warm. Cool on the cookie sheet for 5 minutes. Transfer to a wire rack and let cool.
Drizzle with melted chocolate and sprinkle with crushed peppermint candies, if desired. Makes 16 shortbread wedges.