Preheat oven to 400°F. Line a sheet pan with parchment paper.
In a large bowl combine the flour, baking powder, salt, sugar, and lemon zest. Add the cubes of butter and either with a pastry blender or a fork, cut in the butter until the mixture is grainy and the butter is the size of peas.
Add heavy cream and mix with a spoon until the mixture just starts to come together. Do not overmix. Add the blueberries and gently fold together so as not to crush the blueberries. Gather the mixture into a ball and dump onto a clean surface.
Use your hands to form the dough into a dish about 1.5" tall. Cut into 8 wedges. Place on the sheet pan about one inch apart. Brush scones with more heavy cream.
Bake until golden, about 18-20 minutes until puffed and golden brown. Transfer to a wire rack to cool. Meanwhile, make the glaze.
Stir together the lemon juice and confectioners sugar until smooth, using enough lemon juice to make a thick but pourable glaze. Drizzle over the tops of the scones and let set briefly before serving.
Calories: 374kcal, Carbohydrates: 46g, Protein: 4g, Fat: 20g, Saturated Fat: 12g, Cholesterol: 63mg, Sodium: 160mg, Potassium: 221mg, Fiber: 1g, Sugar: 20g, Vitamin A: 710IU, Vitamin C: 2mg, Calcium: 92mg, Iron: 2mg