Line two cookie sheets with parchment paper.
In a small mixing bowl, whisk together the flour, baking soda, and salt. Set aside.
In a stand mixer or with a handheld mixer, beat together the butter and sugars for 2-3 minutes until light and fluffy.
Add the eggs and beat well to combine. Stir in the vanilla.
Add the flour mixture to the dough, mixing until just combined.
Stir in the pretzels, chips, M&Ms, chocolate chips, and chocolate chunks by hand.
Scoop 2 tablespoon portions of cookie dough onto the prepared cookie sheets, leaving 2 inches between each scoop. Cover with plastic wrap or foil and refrigerate for at least 1 hour and up to 48 hours before baking.
Preheat oven to 350 degrees.
Bake cookies for 9-11 min. Edges should just be light brown and cookies in the middle will appear soft.
Immediately place any additional mix-ins (pretzels, chips, candies, or chocolate chips) on top of cookies, if desired, to add additional color and texture to the cookies.
Let cookies cool on the baking sheet for 5 minutes before transferring to a cooling rack to cool completely.
Store in a sealed container for up to one week.