Preheat the oven to 220°C/200°C fan/400°F/gas mark 6. Line a baking tray with baking parchment.
Mix together the self-raising flour and baking powder in a large bowl until they are well combined.
Add the cold, diced vegan block butter and solid refined coconut oil and rub them in using your fingertips until no lumps of fat remain and the mixture resembles breadcrumbs.The coconut oil in particular can be difficult to rub in so do take your time to ensure that there are no lumps remaining. You can also use a food processor instead for this step (this step only) to save time. Stir in the caster sugar.
Gradually stir in the milk using the back of a knife until it forms a soft, almost sticky dough. If there are any dry, floury bits left in the bottom of the bowl add a drop more milk to mix them in. You may not need to use all of the milk, or you may need a little more.
Bring the dough together into a ball, it should be soft and a bit sticky. Turn it out onto a lightly floured surface, don’t knead it but use your hands to kneaten it a little and pat it out into a round about 4cm/1 ½ inches thick.
Use a floured 6cm/2 ⅓ inch round cutter (plain or fluted is fine) to cut out four scones. Press the cutter straight through the dough, don't twist it. Place them slightly spaced apart on the baking sheet.
Very gently bring the scraps of dough back together, pat out into a round again and cut out two or three more scones.
For the glaze, mix together the milk and maple syrup in a small bowl.
Brush the tops of the scones with the glaze. Don’t let it drip down the sides as that can inhibit the rise.
Bake for 15-18 minutes, until golden. If you tap the underside they should sound hollow, like bread. Remove from the oven and place on a wire rack to cool a little before serving.