Preheat oven to 400 degrees. Place a baking pad or parchment paper on a baking sheet.
In a large bowl whisk flour, sugar, baking powder and salt. Add in cold butter cubes and using a fork, or pastry cutter work the flour mixture.
Fold in blueberries and lemon zest and set aside.
In a small bowl add 3/4 cup heavy cream, lemon juice, egg and vanilla whisk until combined.
Pour wet mixture into dry mixture and using a spoon mix just until combined.
Sprinkle some flour on a surface and lay out dough. Gently form into an 8 inch disk. Using a sharp knife cut the disk into 6 wedges. Place on baking sheet.
Brush the top with the 2 tablespoons heavy cream
Bake 18-20 minutes
Remove from oven and drizzle with lemon glaze
For the glaze
In a small bowl add the sugar, lemon juice and whisk.