Preheat oven to 350°. Unroll piecrusts onto a lightly floured surface. Cut out circles using a 2 ½ -inch drinking glass, re-rolling dough as needed. Place in 1 3/4-inch muffin pans, pressing on bottom and up the sides of each of the mini-muffin cups. Combine melted butter, brown sugar, flour and eggs in a large bowl, mixing well. Add vanilla. Stir in pecans and brickle chips. Spoon pecan filling evenly into pie shells. Bake for 25 minutes, or until filling is set and crust is lightly browned. Cool in pans on wire racks.