In a mixing bowl, combine the bread flour, Dutch-processed cocoa powder, baking soda, espresso powder, and salt and whisk to evenly distribute. Set aside.
In the bowl of a stand mixer fixed with the paddle attachment, cream together the butter, granulated sugar and dark brown sugar on medium speed until light and fluffy, 3-4 minutes.
Add in the vanilla extract and whole egg, then gently mix until incorporated. Add the egg yolks one at a time, mixing in between until each yolk is fully incorporated.
Slowly sprinkle in the dry ingredients in thirds, pausing in between until no more raw flour is visible. Manually fold in the chocolate chips and chocolate morsels. Cover the bowl with cling film and chill in the fridge for at least 1 hour and up to overnight.
Allow the dough to warm on the counter for a few minutes. Meanwhile, preheat the oven to 350℉. Roll individual cookies into ~50g balls, then line on a prepared cookie sheet, leaving 1-2 inches of room in between to account for spreading. Bake the cookies for 11 minutes.
Give the tray a few gentle smacks on the counter, then place the tray back on the stovetop and garnish with more chocolate chips and finishing salt. When the cookies have cooled enough after ~3 minutes, gently transfer them to a wire cooling rack and allow to cool completely.
