Begin by combining the Thai tea mix, whole milk, and half of the heavy whipping cream in a medium saucepan over medium-low heat. Stir continuously until it reaches a steaming point, approximately 5–7 minutes. Do not let it boil.

Once the mixture is steaming, strain it through a fine mesh sieve into a bowl to remove solids. Allow it to cool to room temperature for about 15 minutes.

In a separate bowl, whisk together the sweetened condensed milk and vanilla extract. Pour in the cooled tea mixture and mix thoroughly.

Place your mixing bowl in the freezer for about 15 minutes. Then add the remaining heavy whipping cream and whisk at medium speed for about 3–5 minutes until stiff peaks form.

Gently fold the whipped cream into the cooled tea mixture in three batches using a rubber spatula.

Spoon the ice cream mixture into a freezer-safe container and cover it tightly. Freeze for at least 8 hours or overnight.

Before serving, remove it from the freezer and let it sit at room temperature for 10-15 minutes to soften. Scoop into bowls and enjoy.