Step 1: Melt 4 tbsps of butter in heavy pan. Add marshmallows, stir until melted. Remove from heat and add vanilla and pretzels. Stir to coat. Press mixture into a buttered 9×9 inch pan. Set aside to cool. Unwrap caramels, place in a glass bowl, add 1 tsp of water and microwave for 1 minute. Take out and stir. Place back in microwave for 30 seconds at a time, if needed. Pour mixture over cooled pretzels mixture, while the caramel is still warm, pour the chips over top and lightly press into the caramel. Set in fridge to cool. Slice in the size bar you wish.