to make the dough
in a large mixing bowl or stand mixer, cream the butter, sugars, vanilla and coffee together until fluffy
with the mixer on low, add the flour in slowly, then speed up a bit until it's just incorporated
add in the chocolate chunks or chips and mix just until they are well distributed in the dough
divide the in half
lay a piece of plastic wrap on the counter and place half of the dough on the plastic wrap and use your hands to form into a log about 2 1/2" in diameter.
then use the plastic wrap to tighten up the log and wrap it well.
repeat with other half of dough and then place both logs in the fridge for at least two hours but up to 5 days
when ready to bake
preheat the oven to 350 degrees and line a baking sheet with parchment paper
crack the egg for the egg wash into a small bowl and beat well
take the log of cookie dough out of the fridge, unroll, but leave sitting on the plastic wrap
using a pastry brush or paper towel, coat the outside of the log with the egg wash and then use 1 tablespoon of sugar to coat the outside of the cookie dough log
slice the cookies into about 1/2" slices
place cookies on prepared baking sheets and bake 15-18 minutes until just golden brown
when done, let cool on baking rack completely