Preheat your oven to 400°F (200°C).
In a large bowl, whisk together flour, sugar, baking powder, and salt.
Add cold, cubed butter to the dry ingredients and mix until crumbly.
Gently fold in the blueberries.
In a separate bowl, combine heavy cream and vanilla extract.
Pour the cream mixture into the dry ingredients and stir until just combined.
Turn the dough onto a floured surface and gently knead it a few times.
Pat the dough into a circle about 1-inch thick.
Cut into 8 wedges and place them on a baking sheet lined with parchment paper.
Brush the tops with beaten egg for a golden finish.
Bake for 15-20 minutes until golden brown.