• Preheat oven to 300℉. Gather your ingredients so you have everything close at hand on the counter or table. Line two-9" round cake pans with parchment paper, allowing some to come up the sides of the pans.
• Using a knife or nut chopper, finely chop the pistachios.

Make the Dough

• In a large mixing bowl, cream together the softened butter, powdered sugar, vanilla extract, and salt until light and fluffy, about 2-3 minutes.
• Mix together in a small bowl the all-purpose flour and food-grade lavender. Add to the creamed butter and mix just until combined.

Prepare Shortbread for Baking

• Flatten the dough by hand or use a pastry roller to make a smooth surface, spreading the dough to the edge of the pan. Prick each wedge with a roller docker or a fork a few times.
• Using a sharp knife, score the dough into 16 wedges for each pan. Refrigerate the dough until firm, about 30 minutes.
• Preheat oven to 300°F. Bake for 25-30 minutes, until lightly golden on the edge. Remove from oven and cool for 10 minutes. Using a sharp knife, cut through the score lines. Allow to cool completely in the pan.

Make the Glaze

• While the shortbread cools, prepare the glaze by whisking powdered sugar, whole milk and vanilla extract in a shallow bowl until smooth.
• To glaze the shortbread, you may either hold them by the edge and dip the tops into the glaze to coat or spread the glaze over them with a decorating knife. Place on a wire rack and when you have 4-5 done, sprinkle each with chopped pistachios. Repeat with remaining cookies.
• Allow to set until the glaze has hardened.
• Store in an airtight container until ready to serve. May store at room temperature for 7-10 days. They also freeze well. Makes 32 cookies.