In a food processor or coffee grinder, grind the lavender buds to a fine powder.

In a small bowl, stir together ground lavender buds and granulated sugar. Drizzle in the water. With a fork, mix until a sandy mixture forms, and the sugar clumps together when squeezed.

With your fingertips, firmly pack the damp sugar mixture into the silicone mold.

Use a bench scraper to scrape away the excess. Press the sugar down again, then use the scrapings to fill any holes or gaps.

Sit mold on a small tray. Set aside and allow to dry, uncovered, until sugar cubes are dry to the touch, about 24 hours.

Invert the mold onto a plate or small tray. Carefully pop the sugar cubes from the mold.

Store lavender sugar cubes in a glass jar or airtight container at room temperature for up to 1 year. Use as desired.