In a large bowl add the pretzel sticks and cornflake cereal and mix.
Over the stove, place a sauce pan and turn to medium heat. Add the butter, sugar and corn syrup to the pan and stir until the sugar starts to dissolve, about 3-5 minutes. Once the sugar is dissolved and smooth, remove from the heat and add the peanut butter, salt and vanilla. Once the mixture is smooth, pour over the pretzels and corn flakes. Toss until all of the pretzels and cereal are coated. Let cool until ready to serve and then enjoy.