Prehet oven to 350˚F.

In a small bowl, microwave butter for about 40 seconds until the butter is just barely melted. It should almost be entirely liquid.

Add butter and sugars to the bowl of a stand mixer. Beat together until creamy, about 2 minutes. Beat in vanilla and egg, until just incorporated.

Add flour, baking soda, and salt, beating until just combined. Stir in milk chocolate chips, caramel bits, chopped pretzels, and butterscotch chips until combines.

Roll dough into balls that are about 1 1/2 inches in diameter. Place on cookie sheets lined with silicone mats or parchment paper. They should be spaced a couple of inches apart. Sprinkle evenly with flaky sea salt.

Place in the freezer for 15 minutes or refrigerator for 30 minutes.

Bake for 12 to 15 minutes, until the cookies are puffy and the edges are just golden brown. Make sure that you don't overbake them, they should still be pale and puffy in the center.

Let cool on the pan for 15 to 20 minutes before removing to wire racks to cool the rest of the way.

Store in an airtight container.