Preheat the oven to 350°F (170°C, 160° for a fan oven or Gas Mark 4).
Put the flour, baking powder, salt and sugar in a large bowl and whisk together.
Cut the butter into chunks and add to the flour mixture.
Cut the butter into the flour mixture using a pastry blender, until the mixture resembles fine crumbs.
Mix the grated apples and blackberries into the flour mixture.
In another bowl or pitcher, combine the eggs, milk and vanilla.
Add the wet ingredients to the dry ingredients and stir to combine.
Put a piece of parchment or greaseproof paper onto a cookie sheet.
Sprinkle a little flour on the parchment and place the dough on top.
Sprinkle a little more flour on top and then press the dough into a round, flattened circle about an inch and a bit tall.
Use a sharp knife to cut slices into the dough (as shown in the photograph).
Bake for 20 to 25 minutes or until done.
Cool completely. Then use the knife marks as a guide to cut the scones.