Preheat your oven to 400f and set the rack to the middle level. Line a baking sheet with parchment paper.
In a large bowl mix the flour, sugar, baking powder, baking soda, and salt.
Using the large holes of a box grater, grate the frozen butter and add it to the flour mixture.
Using your hands or a pastry cutter, work the butter into the flour until a coarse meal is formed.
Add the chocolate chips to the flour mixture and stir until incorporated.
In a small bowl, whisk together the sour cream, vanilla extract, and egg.
Using a fork, stir the sour cream mixture into the flour and mix until large clumps form.
Flour your hands and use them to shape the dough into a ball, then place the ball on a lightly floured surface and shape it into an 8-inch circle.
Using a sharp knife, slice the dough into 8 triangles and place them on the parchment paper-lined baking sheet about 3 inches apart and allow to chill in the refrigerator for at least 15 minutes.
Remove the scones from the refrigerator and brush each one with the heavy cream and if using the sugar, add a sprinkle of sugar to the top.
Bake in the oven for 17-20 minutes or until the edges are golden and the top is lightly browned.
Allow the scones to rest for 5 minutes before serving. Serve with raspberry jam and clotted cream and enjoy!