In a medium pot, combine black tea bags, 4 cups of water, 1 teaspoon of vanilla extract, 1 star anise, 4 whole cardamom pods, and 1 cinnamon stick. Bring the mixture to a simmer over medium heat, allowing the water to gently bubble. Once simmering, reduce the heat to low and let it steep for 3-5 minutes until the tea reaches a rich, dark color.

After brewing, carefully pour the tea through a fine mesh strainer into a large bowl or pitcher to remove the spices and tea bags.

Fill two tall glasses with ice, then pour the strained Thai tea over the ice, filling each glass about three-quarters full.

In a separate medium bowl, whisk together 2 tablespoons of sweetened condensed milk and 2 tablespoons of evaporated milk or whole milk until smooth and creamy.

Pour the sweetened milk mixture over the iced tea in each glass, allowing it to swirl beautifully. Optionally, garnish with mint leaves.