Preheat the oven to 350 degrees F and line a cupcake tin with cupcake liners.

In a small mixing bowl, mix together the ground cinnamon, ground ginger, ground cardamom, ground nutmeg, ground allspice, ground cloves, and black pepper.

In a medium bowl, whisk together the flour, baking powder, baking soda, 3 teaspoons of the homemade chai spice mix, and salt. Set to the side.

In a separate bowl, whisk together the milk and sourdough starter discard until smooth. Set aside.

In a mixing bowl, beat the sugar and butter at medium speed for 4-5 minutes until light and fluffy.

Add the eggs, one at a time, beating at medium speed until combined. Add the sour cream and vanilla extract, mixing well.

Alternate adding the dry and wet ingredients to the butter mixture, starting with a third of the flour mixture and then half of the wet ingredients. Mix at low speed until combined, do not overmix.

Divide the cupcake batter evenly into 14 lined cupcake liners, filling 3/4 of the way full.

Bake the Sourdough Chai Cupcakes for 16-17 minutes, or until the tops are golden brown and a toothpick comes out clean.

Remove the cupcakes from the oven, keep in the tin for an additional 5 minutes, then place on a wire rack to cool completely.

In a mixing bowl, beat the butter and powdered sugar at medium speed until smooth.

Add 1 1/4 teaspoons of chai spice mix, the vanilla extract, and a pinch of salt. Mix until combined.

Add 1-2 Tablespoons of heavy cream until desired consistency is reached.

Beat the frosting on medium-high speed for 3-4 minutes or until light and fluffy.