Using a food processor, mix together flour, baking powder, sugar, salt, and lemon zest.
2 cups all-purpose flour (about 250g), 2 ½ tsp baking powder, 3 tbsp granulated sugar, ½ tsp salt, Zest of 1 lemon
Add in the cubed butter and pulse the food processor until the dough mixture looks like sand with a few small pebbles in it. Note: if you don't have a food processor, mix in the cold butter with a pastry blender or your hands.
½ cup 1 stick butter, cubed and frozen
Add the vanilla and stream in the heavy cream while the food processor is running. The dough is ready when it has just started to clump together a little but is still somewhat crumbly. You don’t want to overmix or the scones will be tough. Note: If you don’t have a food processor, you can stir the cream in, a little at a time.
¾ cup heavy cream, 2 tsp vanilla extract or vanilla bean paste