Prepare the Baking Dish: Grease the bottom and sides of a 9×9-inch baking dish with butter. In a small bowl, combine powdered sugar and cornstarch, and sprinkle half of the mixture evenly over the bottom and sides of the dish.
Make the Chai Spiced Marshmallows: Combine gelatin and ½ cup cold water in the bowl of a stand mixer. In a sauce-pot, combine the remaining ½ cup water, granulated sugar, honey, and a pinch of salt. Heat over medium until the mixture reaches 240°F (7-8 minutes).
With the mixer on low, slowly pour the sugar mixture into the gelatin. Gradually increase the speed to high and beat for 8-10 minutes until thick and lukewarm.
Add vanilla, cinnamon, ginger, cardamom, nutmeg, allspice, and cloves to the marshmallow mixture. Mix for 30 seconds until fully incorporated.
Spread the marshmallow fluff into the prepared baking dish and dust with another ⅓ of the powdered sugar mixture. Let it sit for 6 hours. Cut into 1-inch chunks, and dip the sticky sides into the remaining powdered sugar mixture. Set aside.
Prepare the Rice Krispie Treats: Spray a 9×13 baking pan with cooking spray. In a sauce-pot, melt butter over low heat. Add marshmallows, vanilla, and a pinch of salt, stirring until fully melted.
Measure the Rice Krispies cereal into a large bowl. Pour the melted marshmallow mixture into the cereal and stir until well coated. Transfer the mixture into the prepared baking dish, pressing gently into an even layer. Let set for 30 minutes.
Slice into bars and enjoy!