Preheat your oven to 400°F (200°C). Line a large baking sheet with parchment paper or a silicone baking mat to prevent the scones from sticking and to ensure even browning.
In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, baking powder, and salt. Make sure there are no lumps and the leavening agents are well-distributed.
Add the cold, cubed butter to the flour mixture. Use a pastry cutter or two knives to work the butter into the flour until the mixture resembles coarse crumbs with some pea-sized pieces of butter remaining. This step is crucial for a flaky texture.
In a separate small bowl, whisk together the cottage cheese, heavy cream, egg, lemon zest, and vanilla extract until well combined. If you prefer a smoother texture, you can blend the cottage cheese before adding it to the other wet ingredients.
Make a well in the center of the dry ingredients and pour in the wet mixture. Use a spatula to gently fold the ingredients together until just moistened. Carefully fold in the fresh blueberries, being mindful not to crush them.
Turn the dough out onto a lightly floured surface. Gently pat it into an 8-inch circle, about 1 inch thick. Use a sharp knife or a bench scraper to cut the circle into 8 even wedges.
Place the wedges on the prepared baking sheet. Brush the tops with a little heavy cream and sprinkle with coarse sugar if desired. Bake for 18 to 22 minutes, or until the tops are golden brown and a toothpick inserted into the center comes out clean. Transfer to a wire rack to cool slightly before serving.