Mocha Scones

In a medium-sized mixing bowl, add the flour, baking powder, salt, and sugar. Cut the butter into chunks and add it in to the bowl.
Using a pastry cutter, cut the butter into the flour mixture until the butter pieces are quite small.
In a small bowl, whisk together the egg, espresso, and sour cream. Make a well in the center of the flour mixture, and pour the wet ingredients in to the well. Add in the chopped chocolate.
Using a rubber spatula, start to fold the mixture together until the dough starts to come together. Turn the dough out onto some parchment paper or a clean surface, and lightly knead the dough until it just all comes together.
Form the dough into a circle that is ~6.5" in diameter and ~1" thick. Cover the dough and let it rest in the fridge for at least 30 minutes.*
Preheat the oven to 400°F / 205°C. Line a cookie sheet with parchment paper or a silicone baking mat.
Once the dough has rested, cut it into 8 equally sized triangles. Spread the triangles out evenly, and bake for 15 minutes. Let the scones cool completely before glazing them.