The first and most important step for any bundt cake is to prepare the cake pan! Bundts are famously liable to stick to the pan, even if your pan is non-stick, so be sure to grease the pan well with either vegetable oil or melted vegan butter. Pan spray works too.
One trick to ensure a light textured cake is to beat your vegan butter and sugar together in a process called “creaming”. This incorporates air into the batter from the first step and also helps to dissolve the sugar before the cake even hits the oven. Just make sure your vegan butter is at room temperature before trying to beat it, otherwise it might split.
Chai spices include cinnamon, ginger and allspice, but for me the key flavour is cardamom. If you can, try to use the seeds from cardamom pods and grind them yourself in a spice grinder or pestle and mortar. Pre-ground cardamom works too but it tends to lose its flavour very quickly, so be sure to use a fresh jar if possible!