Preheat oven to 375°F. Line two baking sheets with parchment paper or Silpats. Set aside.
Whisk flour, salt, baking soda, and baking powder in a bowl medium bowl, set aside.
Cream butter and sugars together in a stand mixer fitted with the paddle attachment until smooth. About two minutes. Add egg and vanilla and beat until smooth.
On low speed, slowly add in the flour mixture until just combined. Stir in chocolate chips and pretzel M&M's.
Drop heaping tablespoonfuls of dough on prepared baking sheets 2 inches apart. Sprinkle with sea salt. Bake 10-12 minutes until cookies are slightly golden around the edges. Transfer cookies to a cooling rack and let cool completely.