Combine dry ingredients: In a large bowl, whisk together flour, sugar, lemon zest, baking powder, and salt.

Incorporate butter: Grate the frozen butter and blend into the flour mixture until it resembles pea-sized crumbs.

Mix wet ingredients: Whisk together 1/2 cup heavy cream, egg, and vanilla extract in a separate bowl.

Combine mixtures: Drizzle the wet ingredients over the dry, add blueberries, and stir until just moistened.

Form the dough: Turn the dough onto a floured surface, shape into a ball, and flatten into an 8-inch disc. Cut into 8 wedges.

Chill: Brush wedges with heavy cream, sprinkle with coarse sugar, and refrigerate for 15 minutes.

Preheat oven: Set your oven to 400°F (204°C) and prepare a baking sheet with parchment paper.

Bake: Place chilled scones on the baking sheet and bake for 22-25 minutes until golden.

Prepare icing: Whisk confectioners' sugar with lemon juice and drizzle over warm scones.

Store: Keep leftover scones at room temperature for 2 days or refrigerated for 5 days.