Stir coconut milk, almond milk, sugar, coconut oil, brown rice syrup, and vanilla extract together in a saucepan over medium-low heat until sugar is completely dissolved, 3 to 5 minutes; remove from heat.
Blend coconut milk mixture with an immersion blender or in a blender until smooth and creamy. Cool to room temperature.
Transfer whitener to an airtight container and store in the refrigerator.