Preheat your oven to 350°F (175°C) and line your baking sheet with parchment paper.

In a mixing bowl, beat together softened unsalted butter, vegetable oil, and granulated sugar until light and fluffy, about 2-3 minutes.

Mix in the large egg, pure vanilla extract, and chai tea leaves until well combined.

Sift together all-purpose flour, baking soda, salt, ground cinnamon, and optional nutmeg in a separate bowl. Gradually add this dry mixture to the wet ingredients, stirring just until combined.

Cover the cookie dough and refrigerate for 1 hour.

Scoop out portions of dough, roll them into balls, and place them on the prepared baking sheet, gently flattening each ball.

Lightly sprinkle granulated sugar atop each cookie before baking.

Bake for about 9-12 minutes until edges are golden brown but centers are soft.

In a bowl, whisk together powdered sugar, whole milk, and a dash of ground cinnamon until smooth for the glaze.

Once cooled, drizzle the glaze over the cookies and let it set.