In a medium-sized mixing bowl, whisk together the flour, sugar, salt, and baking powder.
Grate the butter directly into the bowl using a cheese grater. Use a pastry cutter or fork to cut the butter into the flour until the mixture forms small, pea-sized crumbs.
Add in your chosen mix-ins
In a separate bowl, whisk together the sourdough starter, egg, vanilla extract, and heavy cream until smooth. Pour this mixture into the dry ingredients and use a fork or dough whisk to gently combine. The dough will be crumbly, but don’t be tempted to add more liquid.
Turn the dough out onto a clean surface and press it into an 8-inch disc. If the dough is sticking, use a small amount of flour to help.
Using a bench scraper or large knife, cut the dough into 8 wedges. Place the wedges onto a parchment-lined baking sheet, leaving space between each one. Pop the baking sheet into the fridge to chill for 20 minutes.
While the dough chills, preheat your oven to 400°F. Before baking, brush the tops of the scones with heavy cream and sprinkle with raw or sanding sugar.
Bake for 20-25 minutes or until the scones are golden brown.
Cool and Enjoy!