Stir yeast and sugar into warm tea, allow to stand for 10 minutes – it should get very bubbly.
In a large mixing bowl, combine flour and salt. Pour in yeast mixture, stir well to combine. Dump dough out onto a floured surface, knead until soft and elastic, 5-10 minutes.
(OR: mix it in a stand mixer with a dough hook for 5 minutes or so!)
Once dough is fully kneaded, place in a greased bowl, cover with plastic wrap, and allow to rise for one hour, or until doubled in size.
Once dough has doubled in size, roll dough out on a floured surface. Aim to make it a large rectangle, say 15 x 20″ or so.
Use a pastry brush to spread melted butter all over the dough – you might not use it all, that’s ok.
Mix together the sugar, spices, and instant tea, sprinkle evenly over the melted butter, reserving a few Tbsp of sugar mixture.
Starting with one of the longer edges, tightly roll the dough up.
Generously grease or spray a 9x 13″ baking pan. Pour any remaining butter in the bottom, spreading evenly before sprinkling with remaining sugar mixture.
Using a very sharp knife, slice the roll into 12 even rounds.
Carefully place each roll into the pan, spacing them evenly.
Cover pan with plastic wrap, allow to rise one more time – about 45 minutes. While waiting for the buns to rise, heat oven to 350F.
(This is what they looked like after the final rise!)
Once final rise is over, pop the pan in the oven and bake for 30-35 minutes, or until golden brown and perfect.
Allow to cool for a few minutes while you make the glaze:
Mix together softened butter, tea, vanilla extract, hot water, and about 1/2 cup of powdered sugar, whisking until smooth. Add remaining powdered sugar, about 1/4 cup at a time, until you have a thick, smooth paste.
Spead over hot Chai Cinnamon buns, allowing it to melt and ooze a little.