Preheat the oven to 350°F.
In a medium size mixing bowl or bowl of your stand mixer, cream the sugar, butter, lavender, and lemon zest on medium speed just until mixed well.
2 ounces (57 grams or 4½ tablespoons) granulated sugar, 4 ounces (113 grams or 1 stick) unsalted butter, softened, 1 teaspoon dried culinary lavender flowers, zest of 1 lemon
Add the vanilla and mix for one minute.
½ teaspoon vanilla
Add the flour and salt and mix. The dough may or may not clump together.
6 ounces (170 grams or 1⅓ cup) bleached all purpose flour, ⅛ teaspoon salt
Pour out the shortbread cookie dough mixture onto a sheet of plastic wrap and knead gently until the dough just starts to come together. Once it does, put it into the refrigerator for 15 minutes.
Roll out the dough to about ¼ to ⅓ inch, and cut it into rounds or other shapes.
Place the lemon lavender cookies on a cookie sheet lined with parchment paper or a silicone mat. They do not need much spacing, but do not crowd them. Place the cookie sheet in the freezer for about 10 to 15 minutes before baking.
Bake for 15 to 20 minutes, depending on the thickness of your lemon lavender shortbread cookies and how long they were in the freezer. The cookies should be slightly firm and the edges just slightly brown. They will become firmer as they cool.
Store in an air-tight container at room temperature.