Start by brewing the chai mixture. Place the whole cloves, cardamom pods, cinnamon sticks, star anise, and peppercorns in a small pot. Toast over medium heat for 1 to 2 minutes, or until fragrant.

Add the water and ginger and gently simmer for 5 minutes, reducing the heat as needed to maintain a gentle simmer. Add the brown sugar and stir until it dissolves.

Remove from the heat and add the tea bags. Cover and steep for 10 minutes.

Set a fine mesh strainer over a wide bowl. Pour the tea mixture through the strainer to remove the spices, tea bags, and ginger. Discard the strained solids. Add the espresso to the tea in the bowl and stir to combine. Set aside to cool.

Make the pumpkin cream: In a large bowl, mix together the mascarpone and vanilla extract.

In another large bowl or the bowl of a stand mixer, stir together the cream, pumpkin puree, brown sugar, and salt. Using an electric mixer or stand mixer fitted with the whisk attachment, beat on medium speed for 5 to 8 minutes, or until soft to medium peaks form. Gradually and gently fold the pumpkin whipped cream into the mascarpone, mixing until just combined.

Assemble the tiramisu. Dip half the ladyfingers into the tea one at a time, leaving each one in the liquid just long enough to coat it on all sides. If it stays in the liquid too long, it will get soggy. Arrange the dipped ladyfingers in a single layer at the bottom of a 9x9-inch or similar baking dish, cutting them if necessary to fully cover the bottom. Spread half the pumpkin cream evenly on top.

Dip the remaining ladyfingers into the tea one at a time, placing them in a single layer on top of the pumpkin cream. Spread the remaining pumpkin cream evenly on top.

Cover and chill in the refrigerator for at least 8 hours or overnight. When ready to serve, combine the ground cardamom, cinnamon, ginger, and cloves in a fine mesh strainer. Dust over the top of the tiramisu, then slice and serve.