Preheat oven to 400°F. Line a baking sheet with parchment paper and set aside.
In a large bowl, whisk together flour, baking powder, salt, and sugar. Using your hands, mix in the butter slices until the dough is crumbly.
In a separate bowl, whisk together cream, eggs, vanilla, and instant coffee.
Gently fold all but two tablespoons of the wet ingredients (save this for brushing the tops of the scones before baking) into the dry ingredients until combined. Fold in the chocolate chips or chocolate chunks.
On a lightly floured surface, turn out the dough and form a round disc, approximately 9 to 10-inches in diameter. Slice into 8 even triangles. Brush with remaining cream mixture and sprinkle sanding sugar over the tops of each scone.
Bake at 400°F for 20 minutes on the middle rack, turning the pan halfway through to ensure even baking.
Notes
Working the dough: Be careful not to overwork the dough. That can result in scones that are heavy and chewy rather than lighter and flaky. When your dough just comes together, it's ready.