Combine the spices and cashew milk in a saucepan, bring to a simmer for 3 to 4 minutes. Add the tea leaves, remove from heat, let steep 2 minutes. Strain. Stir in the espresso if you're using it.
Combine the sugar, cornstarch, salt, and egg (or yolks) together in a saucepan. Whisk to combine. Over low heat, slowly add the milk while whisking. Continue to whisk over low heat until mixture comes to a boil. Boil for 1 to 2 minutes. Remove from heat and add butter and vanilla, continue whisking until butter is fully melted and mixed in.
Pour into small ramekins and chill until set. If you wish to prevent a skin from forming, press a layer of plastic wrap directly onto the surface of the pudding before chilling. Top with yogurt or whipped cream.
This nutritional information refers to each serving of the entire recipe and not just the products used as ingredients.