Bring a kettle of water to a boil and keep simmering (for espresso powder later).
In a medium bowl, add flour, baking soda, baking powder and salt, whisking to combine. Stir in oats.
In the bowl of a stand mixer fitted with the paddle attachment, cream the butter, granulated sugar and dark brown sugar. This means start on low and then increase your speed to medium for about 5 minutes. The mixture should be smooth and lighter in color.
While creaming, measure out ¼ cup of hot water from the kettle. Stir in espresso powder to dissolve. Set aside.
Add the egg and yolk to the butter-sugar mixture and beat until the mixture is fluffy. Scrape down the sides, add the vanilla and beat for a few seconds. Finally, add the dissolved espresso and mix until combined.
Add half the dry ingredients to the bowl and mix until just combined. Be sure to start your mixer on low so the dry ingredients don't go flying! You only want to mix for about 15 seconds. Overmixing will result in tough cookies. Add the remaining dry ingredients and once again, mix only until just combined. Remove the bowl from the mixer and fold in the chocolate chips and ½ cup of the pretzel bits.
Cover the bowl and refrigerate for at least 4 hours.
Preheat your oven to 350°F and place a rack in the center of the oven. Line a baking sheet with parchment paper or a silpat.
Using a spoon, scoop out approximately 2 tablespoons of dough and roll the dough in your hands to form a ball. Place the dough balls on the lined baking sheets about 1 inch apart. Slightly flatten each dough ball into a fat, round disc. Sprinkle each disc with remaining pretzel pieces.
Bake for 12 to 14 minutes, rotating the baking sheet halfway through the baking time. You will know the cookies are done when they start turning golden brown and the edges begin to darken.
Let your cookies cool on the baking sheet for 3 to 4 minutes and then transfer to a cooling rack to cool completely.