Whisk together the flour, cocoa powder, baking soda, and salt in a medium bowl and set aside.
Beat together the butter and sugar (the 1 ¼ cups sugar + 1 tablespoon sugar), and then beat in the egg, egg yolk, molasses, vanilla, and dissolved espresso.
Stir the dry ingredients into the wet and fold in the chocolate chips.
Cover the dough and refrigerate for at least 1 day, but up to 3 days.
Preheat oven to 335F and let dough rest at room temperature 45 minutes. Line 2 half sheet pans with silpat liners.
Use a ¼-cup scoop to measure out the dough and roll it into balls. Bake 6 cookies per half sheet pan one pan at a time until golden along the outside, but still a touch doughy in the center, about 13 to 14 minutes.
Cool before removing from the trays.
Notes
It's important to give the dough time to chill in the fridge for at least one day. This step greatly improves the flavor and texture of these cookies.
To store these cookies, layer them between wax paper in an airtight container and store at room temperature for up to 1 week.