Preheat oven to 400 degrees Fahrenheit and lightly grease or line a large baking sheet with parchment.
In a large bowl, combine flour, sugar, baking powder, and salt. Cut in the butter using a dough blender, fork, or your fingers until the largest pieces are the size of small peas.
In a small bowl, whisk together dried lavender, 3/4 cup heavy cream, egg, and seeds from the vanilla bean (or extract). Gently mix into the dry ingredients until the dough just comes together. On a lightly floured surface, gently knead the dough just enough to make it smooth. Do not overmix. Pat the dough until it is 1/2 inch thick. Cut the scones into squares, triangles, or use biscuit cutters to cut out shapes. Place on prepared baking sheet at least 2 inches apart.
Brush the tops with heavy cream and bake in preheated oven until lightly golden, 10-15 minutes depending on the size. Cool the scones on wire rack until room temperature.
In a small bowl, combine the powdered sugar with the seeds from a vanilla bean or vanilla extract. Stir in 1-2 tablespoons milk until a smooth glaze forms. Drizzle over cooled scones. Sprinkle with dried lavender.
Best served the day they are made.