step1 : Put the butter in saucepan and stir over medium heat until the butter melts.
step2 : Put corn syrup,sugar,brown sugar and condensed milk,stir the mixture to about 20-30 minutes.
step3: Remove from the oven,stir cool slightly,then put the vanilla and stir until to warm enough.
step4: Pour the caramel into a tray laid with a clear plastic. Wait for until the caramel cool completely.
step5: Bring the tray to soak in the refrigerator for 15-20 minutes or until the mixture is well set. Remove from the refrigerator and cut the caramel into small pieces.
step6: Wrapped the caramel by the wax paper or cellophane. Soak it in the refrigerator to eat for several days.