Make the cake:

1. Add the milk and tea to a small saucepan. Heat over medium-low until you achieve a very gentle simmer. Take off the heat and let steep for about 10 minutes. Use a fine-mesh sieve or cheesecloth to remove the tea. You will need 3/4C of milk for the recipe. If after heating you are a little short, top off your measuring cup with extra milk to get you there.
2. Prep your 6″ cake pans by lining with parchment paper and spraying nonstick spray around the sides. Preheat your oven to 350F.
3. In a small bowl, combine the egg whites, vanilla, and 1/4C of the milk. Set aside.
4. To the bowl of a stand mixer fitted with the paddle attachment, add the flour, sugar, salt, and baking powder. Mix on low to combine. Add the butter and with the mixer on low, stream in the remaining 1/2C of milk. Turn the mixer to medium for just long enough to moisten all your dry ingredients.
5. Scrape down the bowl. Turn the mixer onto medium and stream in the egg/milk mixture, continuing to scrape down the bowl periodically to ensure a homogenous mix.
6. Divide the batter evenly between your three cake pans. Bake for about 25 minutes or until a toothpick inserted into the middle comes out clean. (My oven is pretty old, so it takes me a little closer to 30 minutes.)
7. Let the cakes cool in the pan for about 5 minutes and then place on wire racks to cool further.  Once you are able to handle them, lop off the tops to make an even surface.

Make the soak:

1. Whisk together the sweetened condensed milk, vanilla, cardamom, and milk in a small bowl. When your cakes are cool and you are ready to assemble, use a brush to slather on a nice layer of soak to each cake.

Make the frosting:

1. In a saucepan, whisk together the milk, condensed milk, flour, and salt. Cook over medium, stirring often, until a thick paste forms. Remove the pan from the heat, throw the paste in a bowl and refrigerate until cool. It takes about a half hour.
2. In the bowl of a stand mixer fitted with the paddle attachment, cream the butter and sugar together until light and fluffy. This takes about 3-5 minutes on medium-high speed.
3. Turn the mixer to low and slowly add the flour mixture and vanilla. Beat on medium-high until the frosting is light and fluffy. It will take on a very pale, nearly white color.
4. Assemble! Stack soaked cake and frosting and cover the entire thing in another hefty frosting coat.