Make the Chai Sugar Topping by placing ¼ cup granulated sugar and ½ tablespoon of the Chai Spice Mix in a small bowl. Stir to combine. Set aside.
In a bowl, sift together flour, salt and baking soda and stir to combine. Set aside.
In a mixing bowl, cream butter and sugar together until light and fluffy. Add oil, eggs, milk and vanilla extract and mix again to combine.
Slowly add the flour mixture to the mixing bowl with the butter and egg mixture, mixing very thoroughly to combine.
Pour batter evenly into prepared pan, using an offset spatula to spread the batter to the corners. Sprinkle the top evenly with the prepared Chai Sugar Topping.
Bake for 20 minutes, or until the edges are light brown. Cool for 10 minutes in the pan. Cut into 24 squares.