In a large bowl, cream together the butter, brown sugar, and granulated sugar until light and fluffy—about 2–3 minutes. Add in the eggs and vanilla, and beat until smooth.
In a separate bowl, whisk together the flour, baking soda, baking powder, and salt. Gradually add this to the wet mixture, mixing just until combined.
Fold in the chocolate chips, butterscotch chips, pretzels, toffee bits, and any other extras you’re using. Stir until evenly distributed.
Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper. Scoop out dough balls using a cookie scoop or tablespoon, spacing them about 2 inches apart. Bake for 10–12 minutes or until the edges are golden. Sprinkle with flaky salt while warm if desired. Let cool on the pan for 5 minutes before transferring to a wire rack.