A world that has invented such insane ice cream flavors as "balsamic vinegar and black pepper" and "olive oil" somehow never stumbled on the best possible flavor. Which is thai iced tea. And, this recipe is adapted to have absolutely nothing unhealthy in it so go nuts.
A day in advance, freeze the core of your ice cream maker. It takes a long time to cool thoroughly.
A couple hours in advance, boil four cups of water. Put the tea leaves in a tea ball and put this in the boiled water in a mixing bowl. Let it sit for a few minutes, and then stir in the milk powder. This should turn into something thicker than whole milk, which is my way of avoiding using actual cream. You can of course do that if you want something more authentic but also more calorie-dense. Mix well, remove the tea ball, and refrigerate.
Add the eggs, vanilla, and splenda (to your preferred sweetness; bear in mind the frozen product will seem less sweet than the liquid mix) to the milk tea. Use a handmixer to very thoroughly mix this. Then pour this in the ice cream maker. Proceed as per the maker's instructions, keeping in mind that this recipe (without real sugar or cream) will freeze more like ice than normal ice cream.
If you somehow manage to not eat the entire batch directly out of the ice cream maker, put what's left in a separate tupperware - otherwise it will freeze way too hard to the core of the ice cream maker.