Preheat oven to 400F and line a large baking sheet with parchment paper and set aside.
In a large mixing bowl make your flour mixture by whisking all-purpose flour, granulated sugar, salt and baking powder.
Add butter into dry ingredients and using your fingers or a pastry cutter, work in until it resembles a coarse meal. Set aside.
Whisk 6 tablespoons heavy cream and egg in a small bowl, then pour it into the flour mixture. Mix just until combined.
Add blueberries and zest, using a rubber spatula gently fold them into the dough. Don’t worry if some of the berries break up a bit.
On a clean, lightly floured work surface, transfer the scone dough and knead it around until the dough is workable and stays together. Shape the dough into a circle that is about 1 inch thick.
Cut the dough into 8-10 wedges and carefully transfer scones to the prepared cookie sheet, placing them about 1 ½ inches apart. I find a bench scraper helpful to move them to the baking sheet.
Lightly brush unbaked scones with the leftover 2 tablespoons of heavy cream.
Bake for 16-20 minutes or until light golden brown.
Allow scones to cool on the baking sheet for about 10 minutes before transferring them to a cooling rack to add the glaze.
In a small bowl whisk together powdered sugar, heavy cream and lemon juice, adding more liquid as needed for desired consistency and flavor.
Drizzle glaze on the top of the scones and enjoy.