Whisk flour, sugar, salt, and baking powder together in a large bowl. Grate the frozen butter and add to the flour mixture. Combine with a pastry cutter, two forks, or by hand until mixture comes together in pea-sized crumbs. Place in the refrigerator while combining wet ingredients.

Whisk heavy cream, egg, and vanilla together in a small bowl. Drizzle over the flour mixture, add desired add-ins, and mix until everything appears moistened.

Scoop out onto floured surface and with floured hands, form into a rough ball. Dough will be sticky. If it's too sticky, add a little more flour. If it's too dry, add in 1-2 T more heavy cream. Press into 8-inch round and cut into 8 wedges with a sharp knife. Or for 16 mini-scones, divide dough in half and form into two rounds. Then cut each round into 8 wedges.

Brush scones with additional heavy cream, and sprinkle with coarse sugar if desired.

Cover a baking sheet with a silicone mat or parchment paper. Place scones on sheet 2-3 inches apart and refrigerate for at least 15 minutes. (Can move scones to plate to refrigerate instead of pan if baking sheet won't fit in fridge).

Preheat oven to 400 degrees. Bake 18-26 minutes or until golden brown around the edges and lightly browned on top. Larger scones will take longer than mini-scones.

Remove from oven and let cool for a few minutes. If desired, top with a dusting of powdered sugar, a simple icing, melted chocolate, etc.