Add the rice to a blender, cover and blend until it starts to become powdery. Add rice to a medium bowl with the 1 1/4 cup warm water, cashews, star anise, cinnamon stick and orange zest. Cover and let stand at room temperature overnight.
Transfer mixture to a blender, add 2 cups water, cover and blend until smooth.
Line a fine-meshed strainer with 3 layers of cheesecloth. Pass the liquid through, pressing solids to squeeze out any liquid. Discard solids.
Transfer the strained mixture to a large pitcher. Stir in remaining 2 cups water, sugar and vanilla extract. Stir to combine. Serve over ice.