Preheat oven to 365ºF (185ºC). Line 2 large baking sheets with parchment paper or silicone baking mats. Set aside.
Whisk together dry ingredients: 3 ¼ cup (390g) all-purpose flour, 1 ¼ teaspoons baking powder, 1 teaspoon baking soda, and 1 teaspoon salt. Set aside.
Add 1 cup 2 sticks, (226g) unsalted butter softened to room temperature, 1 ½ cups (288g) light or dark brown sugar and ½ cup (100g) granulated sugar to a large mixing bowl and use an electric mixer to beat together on medium speed until combined and creamy, about 2 minutes. With mixer running on low speed, add 2 large eggs one at a time. Then, add in 2 teaspoons pure vanilla extract. Mix until the eggs and vanilla are fully combined.
On low speed, gradually add the flour mixture to the butter/sugar mixture without overmixing.
Gently fold in the 1 cup (170g) semi-sweet chocolate chips, ½ cup (85g) milk chocolate chips, 1 cup (80g) pretzel pieces and ½ cup (100g) caramel bits.
Scoop balls of cookie dough, about 2 tablespoons of dough for each cookie (50g), and arrange 2-3 inches apart on prepared baking sheets. I like to use this cookie scoop. Bake for 10-12 minutes or until edges are slightly browned. The centers should still look soft. While the cookies are still warm, press additional chips and pretzels into the top and sprinkle with flaky sea salt, if desired.
Cool for 5 minutes on the baking sheet. Transfer cookies to a cooling rack to cool completely. Cookies stay fresh covered at room temperature for up to 1 week.