Preheat the oven to 425°F, and line a baking sheet with a silicone baking mat or parchment paper.
Stir together the Greek yogurt and instant coffee in a small bowl until the instant coffee has fully dissolved. In a separate bowl, whisk together the flour, cocoa powder, baking powder, and salt. Cut in the butter with a pastry cutter or the back of a fork until the mixture resembles fine crumbs.
Stir in the prepared Greek yogurt, maple syrup, 3 tablespoons of milk, and vanilla. Gently fold in 1 ½ tablespoons of chocolate chips.
Transfer the dough to the prepared baking sheet, and shape into a ¾” tall circle using a spatula. Brush with the remaining milk. Slice the circle into 8 triangular segments with a sharp knife. Gently press the remaining chocolate chips on top.
Bake at 425°F for 15-18 minutes, or until the tips of each scone triangle in the center of the pan feel firm to the touch. Cool on the pan for 5 minutes before transferring to a wire rack to cool completely.
Drizzle
Stir together chocolate chips and 1 tbsp of oil in a small bowl. Microwave for 20 seconds stir and repeat until chocolate chips are completely melted. Repeat the same steps with the white chocolate in a separate bowl. Just before serving, drizzle melted chocolates on top of the scones.