In a medium saucepan, combine the Thai tea mix, whole milk, and ½ cup of heavy whipping cream. Heat over medium-low until steaming, stirring occasionally, about 5 minutes.

Once heated, remove from stove and carefully strain the mixture using a fine mesh sieve or cheesecloth into a mixing bowl.

Add the sweetened condensed milk and vanilla extract to the strained tea mixture. Whisk until smooth.

Chill your stand mixer bowl for about 10 minutes in the freezer. Add the remaining heavy whipping cream and whip until stiff peaks form, about 3-5 minutes.

Gently fold the whipped cream into the Thai tea mixture in two to three batches.

Transfer the combined mixture to a freezer-safe container and cover tightly. Freeze for at least 8 hours.

Let the ice cream sit at room temperature for 10-15 minutes before serving.