Liberally grease a 4-quart slow cooker with cooking spray and set aside. Meanwhile, in a small bowl, whisk together the egg white and vanilla extract with a fork until foamy and combined.

Pour the nuts into the slow cooker liner and toss with the egg white mixture until most or all of the nuts are coated. This mixture is sticky and will allow the coating to adhere to the nuts better. In a medium bowl, stir together the brown sugar, white sugar, cinnamon, nutmeg, ginger and salt until combined. Pour this mixture evenly over the nuts and toss to coat all of the nuts with the sugar mixture. You may have some extra sugar on the bottom of the liner; that's okay!

Cover the slow cooker and turn it on LOW heat. Cook for approx. 3 hours, stirring every 20 minutes to continue to cook & coat the nuts with the mixture and to prevent burning. In the last 20 minutes of cooking, pour in the water and toss to coat. The water helps the mixture adhere even better and creates that sticky glaze.

Once the time is up, line a rimmed baking sheet with parchment or foil. Spread the nuts carefully and evenly over the baking sheet and allow them to cool. They make stick together in clusters, so gently break apart once they're dry and cooled. Store nuts covered in an airtight container, or break into pieces and serve in mason jars as gifts.