Preheat oven to 350°. Place oven rack in middle position.
In the bowl of a stand mixer with the paddle attachment or using a hand mixer, cream together room temperature butter, brown sugar and granulated sugar on medium speed for about four minutes. Scrape down the bowl occasionally. Add the egg, egg yolk, and vanilla extract and mix for one to two minutes on medium speed.
In a separate bowl combine the all purpose flour, baking soda, baking powder, and salt. Add to wet ingredients and mix together on the lowest speed until just combined.
Chop pretzels into pieces. If using chewy caramel candy cut into bite sized pieces. Add chopped pretzels, caramel candies, chocolate chips and chunks to the dough. Mix on low speed to evenly disperse the mix-ins for about 15-20 seconds. Use a 1/4 cup measuring cup or a large cookie/ice cream scoop to measure out dough. Roll into a ball in your hand and place extra candy, chocolate and pretzels on top of dough if desired.
Bake cookie dough on parchment lined baking sheet at least two inches apart for 10-12 minutes in preheated oven. The center will be set and the edges just slightly golden brown when ready. Use a cookie cutter that is round and slightly larger than cookies to place around the cookies and gently rotate to make perfectly round if desired. Sprinkle with flaky sea salt. Enjoy!
Store in an airtight container at room temperature. Best eaten within one to two days. The caramel is sticky in these cookies while melting so definitely use parchment paper to keep from sticking onto the baking sheet.