In a small saucepan, heat the milk over medium heat just until warm. Don't let it boil.
Remove from heat and add 1 Vanilla Chai teabag. Cover and let it steep for 10 minutes.
In the bowl of your stand mixer, cream the butter and sugar until light and fluffy. Whisk together thoroughly.
In a small mixing bowl, mix flour, baking powder, salt, and the contents of the other 3 teabags.
Beat in eggs, one at a time.
Add vanilla extract, steeped milk, and sourdough starter and beat well.
Now add the dry ingredients to the sourdough mixture one third at a time. Beat well after each addition.
Pour the Sourdough Vanilla Chai Latte Bread batter into your prepared loaf pan. Smooth the top.
Bake in a preheated oven for 50 to 65 minutes. A toothpick or cake tester inserted in the center should come out clean.
Remove from the pan and all to cool on a wire rack for at least 20 minutes before slicing.
Notes
If you want to add a glaze, make sure the bread is completely cool.You can make a quick glaze by mixing 1 Tablespoon of milk with 1/2 cup of powdered sugar.