Preheat oven to 400˚F (200˚C). Line a baking sheet with parchment or lightly grease.
In a large bowl, combine the flour, sugar, baking powder, and salt.
Quickly cut in the butter using a dough blender, two forks, or your fingers until blended and no pieces are larger than a pea.
In a small bowl, whisk together dried lavender, ⅔ cup (158 ml) heavy cream, egg, and seeds from the vanilla bean (or extract).
Gently mix the cream mixture into the dry ingredients until the dough just comes together. Add a little more cream only if the dough is too crumbly to hold. It should not be sticky.
On a lightly floured surface, gently knead the dough just enough to make it smooth. Do not overmix.
Pat the dough into a rectangle about ½ inch (1.25 cm) thick. Cut the scones into 12 squares. Transfer to the prepared baking sheet at least 2 inches (5 cm) apart.
Brush the tops of the scones with a thin layer of heavy cream and bake in preheated oven until lightly golden, 10-15 minutes. Gently transfer the scones to a wire rack and cool to room temperature.
In a small bowl, combine the powdered sugar with the seeds from a vanilla bean or vanilla extract. Whisk in 1-2 tablespoons milk until a smooth glaze forms.
Drizzle the glaze over the cooled scones and immediately sprinkle with a small pinch of dried lavender if desired.
Allow the glaze to set and these Lavender Vanilla Scones are best served the day they are made.
