In a small bowl, whisk together the milk, egg and vanilla extract. Set aside.
In a large bowl, combine the dry ingredients (flour through espresso). Cut in the butter with a pastry cutter, or if you don't have one, your fingers. The dough will resemble coarse crumbs. Stir in the chocolate chips.
Slowly add 3/4 of the egg mixture to the dry mixture and stir gently to combine. Continue adding egg mixture, a tablespoon at a time, just until the dough holds together. If you add too much liquid, the result will be more like muffins than scones. I used all but a tablespoon or two of the liquid. Use picture above for reference.
Turn the dough out onto a lightly floured surface. Pat it into a 10″ circle, about 1″ thick. Cut out 8 equal sized pie wedges and place them on a parchment paper lined baking sheet. Bake for 14 – 16 minutes or until nicely browned. Let cool on a cooling rack.
Meanwhile, prepare the glaze by mixing all the ingredients together. Add more water or sugar to make it thinner or thicker. Drizzle the glaze on scones and enjoy!