Preheat the oven to 350°F. In a large glass mixing bowl, add the butter and cover with a paper towel. Melt it in 30 second intervals or until it’s completely melted (no chunks are left).
Pour in the brown sugar and white sugar and whisk it together.
Whisk in the egg and vanilla extract. Scrape the sides of the bowl to make sure all of the wet ingredients are combined.
Add in the dry ingredients (not the mix-ins yet!): all purpose flour, baking soda, and salt. Mix together (again, scrape the sides of the bowl to ensure everything is well mixed). Note: if the batter is too soft or the butter isn't whisked enough, you may need to add another 2 tbsp - ¼ cup of flour. Mixed batter should resemble this texture.
Add all of the mix-ins to the bowl and fold together.
Line a large baking sheet with parchment paper
Use a 2 inch cookie scoop to scoop dough onto prepared baking sheets. Gently press down so they’re a thick disk cookie instead of a round ball. Press extra chocolate chips and crushed pretzels into the top of the scooped cookie dough balls (this helps create a more visually festive cookie).
Place 6-8 cookies on each baking sheet. They will expand during baking so try to leave at least 2” around each one.
Bake for 9-12 minutes. They will be slightly brown on the edges and look slightly doughy in the center. Use a larger bowl than the cookie method to ‘shake’ the cookie back into a circle shape if they’ve expanded too much while baking.
Let the cookies cool for a few minutes on the pan before removing them to a wire rack. Enjoy warm with flakey sea salt or allow to cool. Both are DIVINE!