In a medium saucepan over medium-low heat, combine the Thai tea mix, whole milk, and ½ cup of heavy whipping cream. Stir occasionally, allowing it to steam for about 5 minutes.

Carefully strain the tea mixture through a fine mesh sieve into a heatproof bowl to separate the tea leaves from the liquid.

Whisk the sweetened condensed milk and vanilla paste or extract into the strained tea mixture until smooth and creamy.

In a separate bowl, whip the remaining 1½ cups of heavy whipping cream on medium-high speed until stiff peaks form.

Gently fold the whipped cream into the tea mixture in three parts, using a spatula to combine without deflating the cream.

Pour the combined mixture into a freezer-safe container and smooth the top. Cover tightly and freeze for at least 8 hours.

Once frozen, let the container sit at room temperature for 10-15 minutes to soften slightly before scooping.

Scoop the Thai Tea Ice Cream into serving bowls and optionally sprinkle with toasted coconut flakes.