In a small bowl, whisk together chai spices until well combined; set aside.

Preheat your oven to 350°F (175°C) and prepare muffin tins with liners or nonstick spray.

In a mixing bowl, combine flour, chai spice mix, baking powder, and salt and whisk together.

In a stand mixer, beat vegetable oil and sugar until fluffy; add eggs and vanilla extract and mix until smooth.

Gradually mix in brewed chai tea and milk; slowly add dry ingredients, stirring gently to combine.

Scoop batter into muffin tins, filling each liner about 3/4 full.

Bake for 15-17 minutes until a toothpick comes out clean; let cool for 5 minutes in tins.

Transfer cupcakes to a wire rack to cool completely before frosting.

Beat softened butter until fluffy, then gradually add powdered sugar and remaining chai spice mix until creamy.

Once cool, pipe chai-spiced buttercream onto each cupcake using a piping bag.