You can make the tangzhong in a saucepan or the microwave. For the saucepan method, whisk the flour and water together until the flour dissolves. Place the saucepan over medium heat and stir the mixture frequently. In about 30 seconds to 1 minute, the flour will start to thicken. Stir constantly until the watery liquid absorbs into a thicker paste. Turn off the heat and transfer the tangzhong to a bowl to cool.

For the microwave method, whisk the flour and water together. Then, heat the mixture for 30 seconds on high. Take the bowl out of the microwave, stir everything and check the consistency of the mixture. If the tangzhong is still quite runny, microwave it for another 10 seconds and stir. If it has formed already, stir and let it cool. Otherwise, heat the mixture at 5-second intervals, stirring in between, until you get a thick paste. Be patient and resist the urge to stick the tangzhong in the microwave and heat it for a longer period. The tangzhong can easily overheat, leaving you with a stiff block of cooked flour.

Lightly grease a large mixing bowl with oil. Set it aside.

In a microwave-safe bowl, heat the milk in the microwave on high for about 30 to 40 seconds. Use a thermometer to check the temperature of the milk. It should be somewhere around 105ºF to 120ºF. If the milk isn’t hot enough yet, heat it again for 5 to 10 seconds. If the milk is too hot, quickly whisk the milk and let it cool for several minutes.

Add 1 tablespoon of sugar and yeast to the milk. Stir to hydrate the yeast. Let it sit for 5 to 8 minutes while you prepare the other ingredients. After 5 to 8 minutes, you should see a layer of foam on the top at least 1/4 inch thick (an indication that the yeast is active).

In the bowl of a stand mixer, add the all-purpose flour, sugar, milk powder, salt, egg, lemon zest, tangzhong, milk/yeast mixture, and melted butter.

Fit the mixer with the dough hook. Mix the dough on low until you don’t see any loose flour on the sides of the bowl. This should take 30 seconds to 1 minute. Then, increase the speed to medium-low and work the dough for 7 minutes. You may need to scrape down the sides of the bowl occasionally.

Scrape the dough out of the bowl onto a lightly floured surface and knead a few times. If the dough is feeling tacky, lightly dust your hands with flour.

Shape the dough into a ball and place inside the greased mixing bowl. Cover the bowl with a damp towel (or a silicone lid) and let it rise in a warm place for about 1 hour, until the dough doubles in size.

Rinse out the bowl of the stand mixer and dry with a towel. Add the butter and brown sugar to the bowl.

Fit the mixer with the paddle attachment. Cream the butter and sugar on low for about 30 seconds to a minute. Scrape down the butter from the sides of the bowl, if necessary. Increase the speed to medium-low and mix the butter for another 1 to 2 minutes, until the sugar is well incorporated and the butter is starting to look fluffy.

Add the cinnamon, cardamom, and vanilla and mix on low until the cinnamon is well incorporated. Transfer the filling to a bowl.

Heat the saucepan over medium-high heat until the liquid bubbles. Reduce the heat to medium-low and let the glaze simmer for another 2 to 3 minutes. Don’t let the glaze simmer for much longer as it can burn. Remove the saucepan from heat and let the glaze cool.

Grease the baking pan with some oil. Lay a piece of parchment over the pan, making sure there’s about 1 1/2 inches of overhang along the longer sides. The oil should help keep the parchment in place.

Punch down the dough to release excess air. Turn the dough over a lightly floured surface and shape it into a large oval. If the top of the dough is greasy, lightly sprinkle some flour on top.

Roll out the dough to a 18x12-inch rectangle.

Scoop out the filling and spread it onto the dough rectangle. Make sure to spread the filling up to the edges of the dough rectangle.

Grab onto a long edge of the dough and roll up the dough into a log. As you roll up the dough, make sure the sides are rolling up straight and not caving in. That helps to ensure that the rolled up dough is evenly thick throughout. I usually measure the log here to make sure it’s about 18 inches long.

Slice the log into 12 equal pieces, about 1.5 inches wide. I like using a sharp serrated bread knife for this. You can also use any sharp knife or dental floss.

Place the rolls cut side down inside the parchment-lined pan. Cover the rolls with plastic or a damp towel. Let the rolls rise in a warm place for 45 minutes to 1 hour, until they double in size. The time depends on how hot or cold the environment is. During the winter time, it can take as long as 1 hour 15 minutes to double in size.

Preheat the oven to 350ºF and arrange an oven rack to the middle position.

Brush the lemon glaze over the rolls. Let the rolls cool for another 5 minutes before serving. Enjoy the rolls warm.

Store any remaining rolls in an airtight container at room temperature. They will keep for several days. To reheat, microwave the rolls on high heat for 10 to 15 seconds. You can also heat them in the oven at 325ºF for 8 to 10 minutes.