To make the chai spice. In a shallow bowl, combine the cinnamon, ginger, cardamom, nutmeg, all-spice, cloves, and pepper. Reserve the chai spice blend for the cupcake batter and frosting.To make the cupcakes. Preheat oven to 350° F. Line 24 cupcake molds with paper liners.Bring the milk to a boil in a small pot. Remove from the heat and add the tea bags, cover, and steep 10 minutes.In a large mixing bowl, beat together the butter and sugar until light and fluffy. Add the vanilla and sour cream, beating until smooth. Beat in the eggs, one at a time, until combined. Add the flour, baking powder, baking soda, salt, and 3 teaspoons of the chai spice mix. Stream in the chai milk, beating until just combined. Divide the batter evenly among the prepared pans. Transfer to the oven and bake 22-25 minutes, until the tops are just set, and no longer wiggly in the center. Remove and let cool.To make the frosting. Melt together 1 stick butter, brown sugar, and cream in a medium saucepan. Bring to a boil and cook 2 minutes, or until the sugar has dissolved. Add a pinch of salt. Remove from the heat and add to the bowl of a stand mixer. Place the bowl in the freezer (or fridge for longer) for 15 minutes or until cool to touch.Grab the cooled butter mixture from the freezer and add the remaining 1 stick butter, vanilla, powdered sugar, and 1-2 teaspoons chai spice to the bowl. Beat together until well combined, adding more sugar as needed. Frost each cupcake and sprinkle with Caramel Brûlée (recipe in notes). Add cinnamon sticks, if desired.