Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
In a large bowl, whisk together the flour, sugar, baking powder, and salt.
Cut in the cold butter using a pastry cutter or your hands until the mixture resembles coarse crumbs.
In a separate bowl, whisk together the buttermilk, egg, vanilla extract, and lemon zest.
Gradually add the wet ingredients to the dry ingredients, mixing until just combined.
Gently fold in the raspberries, being careful not to overmix.
Turn the dough onto a floured surface and shape it into a disc about 1 inch thick.
Cut into 8 wedges and place them on the prepared baking sheet.
Brush the tops with heavy cream and sprinkle with coarse sugar.
Bake for 18-22 minutes, or until golden brown. Let cool slightly before serving.