I use English Breakfast tea for this. It's a readily available black tea that's generally fixed with milk and sugar, so it works well.
I add the spices and teabags to a large bowl, add the boiling water, stir, and steep it for 20 minutes or so.
Then, I remove the teabags and strain it through my yogurt cheese maker a couple of times to filter out the sediment from the spices. Using whole cardamom, nutmeg, cloves, etc., would simplify things, but I have an easier time finding ground spices here, so that's what I use.
After it's been well strained, I stir in the sugar, honey, and vanilla, and store it in the fridge in a Mason jar.
You may need to tweak the spice and sweetener proportions according to your taste, but this tastes pretty spot on to the latte I get at my favorite café, and
it includes all of the spices listed on their menu, plus the honey that I can most definitely taste :)
When I want a chai latte, I mix the heated syrup about 50/50 with frothed soy milk. I used to have a really nice super automatic Jura Capresso
, but my equipment is a bit more humble these days, so I just use the microwave and a frothing wand
And it seems to work just fine :)