In a large bowl whisk together the flour, sugar, baking powder, salt, cinnamon, and nutmeg.
Add the cold diced butter and using your fingertips, rub the butter into the flour mixture until it resembles coarse crumbs. Toss in the chocolate and mix gently with your hands to combine.
In a separate small bowl whisk with a fork the heavy cream and vanilla until combined.
Create a small well in the center of the flour mixture. Pour the cream mixture into the well, and stir with a fork until the dough comes together.
Turn the dough out onto a floured surface. Form the dough into a disk about 1” (2.5cm) thick by 6” (15cm) round. Cover with plastic wrap and refrigerate for 30 minutes.
After 30 minutes, cut into 8 wedges by pressing straight down with a large sharp knife. Important: do not saw through the dough, which can cause the scones to collapse while they bake. Transfer to a parchment-lined cookie sheet and pop your tray into your fridge for 15 minutes while you preheat the oven.
Preheat oven to 375º F (190º C).
Brush the scones with heavy cream and bake for about 18 to 20 minutes or until risen and golden brown. Remove from oven and allow to cool down completely on a wire rack.
Prepare the vanilla glaze (optional): Mix the ingredients in a small bowl until smooth.
Drizzle glaze over scones, if using, and serve.