You'll need all-purpose flour, bread flour, cornstarch, baking soda, salt, sugars, butter, espresso powder, vanilla, egg yolks, and chocolate.
Mix the dough
Cream together the sugars, butter, and espresso powder. Add in the vanilla and egg yolks and beat until fully combined. Add in the dry ingredients and mix on low speed until just combined. Lastly, fold in the chocolate.
Scoop & bake
With a 2 tbsp cookie scoop, place balls of cookie dough on a parchment lined baking sheet. Top with more chocolate and bake!
Allow the cookies to cool on the baking sheet, then top with flaky sea salt and enjoy!