In the bowl of an electric mixer, preferably with a paddle attachment, mix the butter and sugar until combined. Add the vanilla and lemon zest.
In another bowl, combine the flour, salt and dried lavender and add to the butter mixture. Mix until the dough just starts to come together.
Dump onto a floured surface and combine the dough using your hands until it comes together into a disc. Divide the disc into 2 and wrap each in plastic wrap. Chill in the refrigerator for about 30 minutes.
Roll out each dough disc on a floured surface to about ¼ inch thick. Use a cookie cutter to cut the dough and then transfer to an ungreased baking sheet. Top with desired topping (sanding sugar, dried lavender, etc).
Bake for about 15 minutes or until the cookies begin to turn light brown. Cool on a wire rack.
Notes
The dough can be frozen prior to baking.
Make sure to purchase food grade lavender.
Finely chop the lavender until almost a powder. You can also use a mortar and pestle.