Preheat oven to 400 F. Combine flour, baking powder & sugar in a large bowl and mix together. Add buttermilk & egg, combine with dry ingredients until a shaggy dough forms.
Transfer to a clean surface and gently bring dough together with your hands. Flatten into a square and fold in half, then fold again once more. Flatten once again and cut circles for your biscuits.
Add to a cast iron skillet and have dough touching. Coat with heavy cream and sprinkle with course sugar Bake for 10-15 mins until golden brown.
While biscuits are baking, create blueberry topping by adding all ingredients to a saucepan and heating over medium heat until it comes to a gentle simmer. Turn off heat and transfer to airtight container, store in fridge for 20 mins before serving.
Whisk heavy cream & vanilla on high until steam peaks form.
Assemble shortcake by separating biscuit in half and layering with whipped cream and blueberries.