On a cutting board, using the back of a chef's knife, crush the black peppercorns, cloves, and cardamom pods. Place them in a medium saucepan over medium heat. Add the ginger and cinnamon sticks and toast for 2 to 3 minutes, or until fragrant.

Add the water and bring to a boil over medium-high heat, then reduce the heat to medium-low and simmer for 10 minutes.

Add the tea bags, turn off the heat and cover the pot so the tea can steep for 5 minutes. Discard the tea bags and pour in the sugar. Stir until the sugar dissolves. Pour the tea through a strainer and set aside. If you're moving super fast through this recipe, you may need to transfer the bowl of chai tea to the fridge to chill faster.

In the stand-up mixer (with the whisk attachment) or using a hand-held electric mixer, combine the mascarpone, sugar, egg yolks, dark rum, heavy cream and salt. Beat for about two minutes, until light and fluffy. The mixture should fall back onto itself.

Spread about 1/3 cup of the mascarpone filling onto the bottom of a 2-quart baking dish. Dip about 6 to 7 lady fingers, one by one, into the chai tea, arranging them side by side. If there's a gap between the lady fingers and the baking dish, place a few in the opposite direction.

Spread about 1/2 cup of the mascarpone filling atop the lady fingers. Repeat layering with the remaining two layers. Smooth the top layer of mascarpone filling until nice and even. Lightly cover the tiramisu and transfer to the fridge to chill for at least 2 hours (or up to 1 day). Dust the top with the cocoa powder.