• Preheat oven to 400 degrees and line a baking sheet with parchment paper.
• In a large bowl, whisk together flour, sugar, baking powder, baking soda, and salt.
• Cut in butter with a pastry blender or fork (or your hands), until pea-size pieces form with some larger chunks remaining. Stir in lemon zest.
• In a small bowl, whisk together buttercream, egg, fresh lemon juice, and vanilla. Using a spatula, fold the wet ingredients into the dry mixture until just combined.
• Place dough on a lightly floured surface and flatten it into a rough rectangle. Fold the dough in half and press on it to flatten layers together and re-shape into a rectangle. Now, fold the dough in half again going in the opposite direction. Try to work quickly as you don't want butter to get warm.
• Form the dough into a circle about 1" thick. Slice dough into 8 triangles (I like to use a bench scraper to do this) and place on prepared baking sheet. Brush scones lightly with buttercream or heavy cream.
• Bake for 14-17 minutes, until scones are just turning golden around edges.
• Let scones cool before drizzling with vanilla icing.

Vanilla Icing

• In a medium bowl, whisk together confectioners' sugar, buttermilk, and vanilla extract until smooth.