Preheat oven to 350°F. Line a 12-count cupcake tin with paper liners. Set aside.
Place the milk and chai tea bags in a small saucepan set over medium heat. When the milk starts to steam, remove it from the heat and set it aside to steep for 5 minutes.
½ cup whole milk, 2 chai tea bags
While the tea steeps, in a large bowl, whisk the flour, brown sugar, baking powder, and chai spice together. Set aside.
1½ cups all-purpose flour, 1 cup brown sugar, 1 teaspoon baking powder, 2 teaspoons chai spice
In another bowl, stir together the chai milk (make sure to remove the tea bags first), vegetable oil, eggs, and vanilla.
½ cup vegetable oil, 2 large eggs, 1 teaspoon pure vanilla extract
Add the wet ingredients to the dry and whisk just until no large lumps of flour remain.
Divide the mixture between the cupcake wells, filling about ⅔ full, and bake for 15-18 minutes, or until a toothpick inserted into the center comes out clean.
Remove the cupcakes to a wire rack and cool completely before icing.