In a medium bowl, whisk the flour, baking soda, and salt together. Set aside.
1¾ cups all-purpose flour, 1 teaspoon baking soda, ½ teaspoon kosher salt
In a large bowl, whisk the melted butter and sugar together until well combined.
¾ cup unsalted butter, 1 cup brown sugar
Add the egg and vanilla and whisk until the mixture turns pale yellow, about 2-3 minutes.
1 large egg, 1 teaspoon pure vanilla extract
Add the dry ingredients to the wet ingredients and mix until a shaggy dough forms, about 30 seconds.
Gently fold the chocolate chips and chopped pretzels into the dough, being careful not to break up the pretzels too much.
1 cup dark chocolate chips, ½ cup chopped pretzels
Tightly cover the dough and refrigerate for 30 minutes. While the dough chills, preheat oven to 375°F. Line 2 large baking sheets with parchment paper. Set aside.
Remove the chilled cookie dough from the refrigerator. Use a cookie scoop to scoop 2-tablespoon-sized dough balls onto the prepared baking sheets, making sure to place them at least 2 inches apart.
Bake for 12-14 minutes, or until they edges begin to lightly brown.
Let the cookies cool completely on the baking sheet. They'll continue to set as they cool. While the cookies are still warm, sprinkle with sea salt flakes.
Sea salt flakes