1. In a bowl, cream the butter, brown sugar, and salt until light. Add the flour and lavender. Mix well, then refrigerate and chill for about an hour.
2. Preheat oven to 400°F. Grease a heavy cookie sheet.
3. Turn dough out onto a lightly floured board and roll to 1/3 inch thick. With a small biscuit cutter, cut the dough into rounds and place on the cookie sheet.
4. Bake for 8–10 minutes, or until delicately browned. Cool on a wire rack, sprinkling with confectioners’ sugar while still warm.