In a medium saucepan, combine the rhubarb, cardamom, maple syrup, rose water, and vanilla extract. Bring the mixture up to a gentle simmer and cook over medium heat for about 7-10 minutes, until the rhubarb is soft and jammy. Let cool to room temperature.
In an upright blender, combine all of the stewed rhubarb with the dairy-free milk and blend until smooth. Transfer to an air-tight container and let chill completely in the refrigerator. Serve the rhubarb milk on its own over ice, over iced matcha, or blend with a frozen banana to make it into a smoothie.
Recipe by Golubka Kitchen at https://golubkakitchen.com/rhubarb-milk/