1. In the bowl of a food processor, add flour, cocoa powder, sugar, salt, and baking soda. Pulse to combine thoroughly. Add butter and pulse a few more times chunks begin to form. With processor running, add milk and vanilla until the mixture comes together. Transfer the cookie dough to a work surface and knead to incorporate ingredients. Divide the dough in half and shape each half into a long and narrow log, about 1¼ inches to 1¾ inches in diameter. Wrap each log in plastic wrap and refrigerate for at least 2 hours or up to a week.

2. Preheat oven to 350° F. Line baking sheets with parchment paper. Slice dough into 1⁄8-inch thick slices and place on baking sheets about 1 inch apart. Bake 10-12 minutes. Cool cookies on wire racks.

Lavender Vanilla icing:

1. Steep lavender in 1/4 cup of milk overnight. Strain into small bowl or measuring cup for later.

2. Sift powder sugar into medium size bowl. Add 2 tablespoons lavender milk, vanilla, pinch of sea salt and stir until smooth. Icing will be thick but spreadable. Spread on wafer cookies and garnish with dried lavender.