Warm the milk: Pour milk into a microwave-safe measuring cup and microwave 40-45 seconds, or to about 110ºF (like warm bath water). Make sure it is not scalding, as it could kill the yeast.

Transfer the warm milk to the bowl of an electric mixer. Sprinkle yeast on top. Add sugar, egg, yolk, and melted butter (warm, not hot). Mix until fully combined.

Stir in flour and salt with a wooden spoon until a dough begins to form.

Place dough hook on stand mixer or electric hand mixer, and knead dough on medium speed for 8 minutes. The dough should form into a structured, stretchy ball and be slightly sticky to the touch. (If too wet or sticking to the bottom of the bowl, add in 1-2 Tbsp additional bread flour.)

Transfer the dough ball to a well-oiled bowl, and cover with plastic wrap and a warm towel. Place in a warm spot (such as a slightly warm oven, turned off, with the door cracked) and let it rise 1 - 1.5 hours, or until doubled in size.

After the dough has doubled in size, turn it out onto a well-floured surface. Roll it out into a 14x9-inch rectangle, the long axis oriented horizontally.

Make the filling: In a small bowl, add the softened butter, vanilla bean paste, earl grey, sugar, lemon, and honey, and mix until fully combined and smooth.

Evenly spread the filling over the dough, leaving a ¼-inch margin at the far end of the dough.

Use a pizza cutter wheel to slice the dough into 9 equal vertical strips, each about 1.5 inches wide. Tightly roll each strip of dough away from you into a pinwheel. (Alternatively, roll the whole rectangle into a 14-inch-long log, starting at one end and progressively tucking the edge closest to you under, then rolling tightly away from you. Then, using a serrated knife or unscented floss, cut the log into 9 equal rolls, about 1.5 inches each.)

Prepare a 9x9-inch baking pan or 9-inch round cake pan by greasing with cooking spray or butter and lining the bottom with parchment paper.

Place buns in the prepared pan, pinwheel side facing up. They should be close enough to barely touch each other but with room to expand.

For the overnight option: Cover the pan tightly with plastic wrap and refrigerate overnight. In the morning, remove the pan from the fridge, loosen the plastic wrap to allow room for expansion, and cover with a warm towel. Bring to room temperature on the counter, and let rise until doubled in size, about 1.5 - 2 hours in total. For the same-day option: Cover loosely with plastic wrap and a warm towel, and let rise again until doubled in size, about 45 minutes.

Preheat oven to 350ºF. Remove plastic wrap and towel. Bake the buns 20-25 minutes, or until just golden on the edges.

Make the glaze: Heat the cream to just below boiling in the microwave or a tiny saucepan. Add the tea bag and steep about 10 minutes, pressing the bag to extract as much tea as possible. Remove the tea bag. Add tea-infused cream to a mixing bowl with powdered sugar and vanilla, and whisk until smooth.

After removing the buns from the oven, drizzle with the glaze. Serve immediately.

Wrap any leftover buns tightly with plastic wrap and store in refrigerator up to 3 days.

To reheat leftover buns:

Oven or toaster oven: Preheat oven or toaster oven to 350ºF. Place cold buns on a large sheet of foil. Pour about 1 Tbsp water (per bun) over and around each bun. Wrap them up in the foil so they are completely covered. Place in the heated oven for 10 minutes, or until warmed through.

Microwave (in a pinch): Place one bun on a microwave-safe plate. Wet and squeeze a paper towel, then wrap the damp paper towel over and around the bun. Mcrowave about 20-30 seconds, or until soft and heated through.