In the order listed, add the first 5 ingredients to a high-power blender. Turn the machine on and gradually increase to the highest speed. Blend for 30-40 seconds, using the tamper to press the ingredients toward the blades, until the mixture is thick and resembled ice cream.
Add the Earl Grey concentrate and blend 10-20 seconds, or until smooth. (For a thinner shake, add an additional 1/2 cup soy milk.) Pour into four glasses and top with whipped topping, if desired.
Earl Grey Concentrate
Bring the water to a rapid simmer; pour into a mason jar or other heat-proof container. Add the tea bags and maple syrup. Let steep 10 minutes. Discard the tea bags. Keep the concentrate refrigerated (this will make more concentrate than you need for the milkshakes.)