Preheat oven to 400 degrees and line a baking sheet with parchment paper.

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

Use a pastry cutter to cut cold butter into flour mixture until breadcrumb texture is achieved. 

In a small bowl, combine heavy cream, egg and vanilla extract. Whisk until well combined.

Create well in center of flour mixture and add cream mixture. Stir just until combined. Gently fold in blueberries. 

Transfer dough to lined baking sheet and pat into a nine inch round shape. Cut into 8 equal pieces, do not separate. Brush with heavy cream and sprinkle with sugar. Bake until golden brown.