Gather all the ingredients. Preheat oven to 400°F. Line a baking pan with parchment paper. Set aside.
Add the flour, baking powder, salt and sugar into a large bowl. Whisk to combine.
Grate cold butter directly into the flour. Using your fingers or pastry blender, work grated butter into the flour until the texture is crumbly.
Add in the lemon rind and blueberries. Stir in gently to mix with dry ingredients.
In a separate container, whisk together all the wet ingredients - cream, egg and vanilla until well combined.
Pour carefully over the prepared flour mixture. Stir to combine, until the flour is moistened.
Tip the dough onto a lightly flour working surface. Gently but firmly shape the dough into a round disc. Pat into shape and cut into 12 wedges.
Transfer to the prepared lined pans.
Brush each wedge with cream, and sprinkle with sugar if desired.
Bake in the oven for 25 minutes, or until the tops are golden brown. To check for doneness, insert a toothpick or cake tester into the scone. It should come out dry.
Remove from heat and transfer to cooling racks.
The scones are delicious served warm, or at room temperature.