1-Whisk flour, sugar, salt, and baking powder: Whisk flour, sugar, salt, and baking powder together in a large bowl. Grate the frozen butter using a box grater. Add it to the flour mixture and combine with a pastry cutter, two forks, or your fingers until the mixture comes together in pea-sized crumbs. Place in the refrigerator or freezer as you mix the wet ingredients together.
2-Whisk 1/2 cup heavy cream, the egg,: Whisk 1/2 cup heavy cream, the egg, and vanilla extract together in a small bowl. Drizzle over the flour mixture, add the add-ins, then mix together until everything appears moistened.
3-To make triangle scones: To make triangle scones: Pour onto the counter and, with floured hands, work dough into a ball as best you can. Dough will be sticky. If it’s too sticky, add a little more flour. If it seems too dry, add 1-2 more Tablespoons heavy cream. Press into an 8-inch disc and, with a sharp knife or bench scraper, cut into 8 wedges. For smaller scones, press dough into two 5-inch discs and cut each into 8 wedges. To make 10-12 drop scones: Keep mixing dough in the bowl until it comes together. Drop scones, about 1/4 cup of dough each, 3 inches apart on a lined baking sheet. To make mini (petite) scones, see recipe note.
4-Brush scones with remaining heavy cream and: Brush scones with remaining heavy cream and for extra crunch, sprinkle with coarse sugar. (You can do this before or after refrigerating in the next step.)
5-Place scones on a plate or lined: Place scones on a plate or lined baking sheet (if your fridge has space!) and refrigerate for at least 15 minutes.
6-Meanwhile, preheat oven to 400°F (204°C): Meanwhile, preheat oven to 400°F (204°C).
7-Line a large baking sheet with parchment: Line a large baking sheet with parchment paper or silicone baking mat(s). If making mini or drop scones, use 2 baking sheets. After refrigerating, arrange scones 2-3 inches apart on the prepared baking sheet(s).
8-Bake for 18-26 minutes or until golden: Bake for 18-26 minutes or until golden brown around the edges and lightly browned on top. Larger scones take closer to 25 minutes. Remove from the oven and cool for a few minutes. Feel free to top with any of the toppings listed in the recipe Note below.
9-Leftover scones keep well at room temperature: Leftover scones keep well at room temperature for 2 days or in the refrigerator for 5 days.