For the Dirty Chai Tiramisu:

1. Lightly crush the spices in a mortar and pestle or with the back of a knife.
2. Add to a dry saucepan with the ginger and toast on medium for 1-2 minutes or until fragrant, then add in the water.
3. Bring to a boil, then reduce to a simmer and add tea or tea bags to steep for 5 minutes. 
4. Shut off the heat and strain the tea mixture into a bowl, then whisk in the sugar and espresso powder until combined. Add the rum and set aside in the fridge to let cool completely while you work on the mascarpone filling.
5. Add egg yolks and sugar to a bowl and using an electric mixer or stand mixer, beat for 5 minutes or until pale in color and slightly thickened. Add mascarpone, heavy cream, and vanilla and beat until combined. Fold in the cinnamon, cardamom, and salt. 
6. Start assembling your tiramisu in an 8×8” or 9×9” baking dish. Dip the lady fingers in the chai mixture for about 3 seconds (a quick double dunk should do the trick). Don’t dunk them for too long or else you run the risk of them falling apart. Place the ladyfingers in the bottom of the baking dish, breaking them in half if needed to fit the bottom. You should use around ~12 lady fingers per layer depending on the size of your dish.
7. Add half the mascarpone filling and spread evenly using a spatula. Repeat the layering process to add another layer of soaked ladyfingers and spread the rest of the mascarpone filling over top.
8. Cover the tiramisu with plastic wrap and place in the refrigerator to set at least 4-6 hours, ideally overnight. 
9. When ready to serve, dust lightly with cinnamon and enjoy!