Using a medium-large food processor (ours is 9 cups), 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 press the "pulse" button on the food processor a few times until the dough mixture looks like sand with a few small pebbles in it. Note: if you don't have a food processor, use grated frozen butter for best results and mix it in with the dough until it's fully coated in the flour mixture but not softened or melted.
½ cup butter, cubed and frozen (1 stick)
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 in little bits 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 in the cold cream, a little at a time.
¾ cup heavy cream, cold (fridge temp), 2 tsp vanilla extract or vanilla bean paste