Shred the carrots thinly and squeeze out all the liquids from them. This step is important as you do not want high water content in the filling.

Add the shredded carrots and cook on medium heat until they start to change color and the moisture starts drying out.

Add the condensed milk, then add the spices (I use cinnamon and nutmeg, but you can also add ginger or cardamom powder) and mix until combined.

Cream the butter, sugar, and salt using a whisk attachment until fully combined, for 3-5 minutes. Add the egg and mix for 1-2 minutes.

Add the flour, lukewarm milk (35-40 degrees Celsius), and instant yeast and mix using a spoon or spatula until the dough starts to come together.

If you are using a stand mixer, switch to the dough hook attachment. If not, use your hands to start kneading the dough. The dough will be sticky and wet at first but should become smooth, soft, and not sticky by the end. The kneading process can take up to 20 minutes if done by hand. If the dough is still very sticky after 5 minutes of kneading, add 15 to 20 grams of flour to the dough, a little at a time.

Test if the dough is done by doing the windowpane test – cut a small piece of the dough and stretch it using your fingers. The dough should be able to stretch to paper thinness and be translucent without breaking. If the dough breaks during the test, knead it for a few more minutes.

Lightly oil a bowl, place the finished dough inside and turn it around so that all sides of the dough are lightly coated with oil. Cover with cling film and let it rise in a warm place for 1.5 to 2 hours until it doubles in size.

Punch the dough, then place a baking sheet on the surface and transfer the dough to it. Lightly flour the rolling pin and roll the dough into a rectangle (around 14×18 inches). Don't roll the dough too thin; keep the thickness to around 2/3rd inch. If the dough is too thin, the rolls will be tough and chewy rather than soft and fluffy.

Spread a layer of the carrot filling on the dough, making sure all the edges are covered.

Roll the dough horizontally (breadth-wise) slowly, making sure you are tightly tucking it in, and roll it all the way through until it forms a cigar shape. If it does not work in the first go, unravel it and do it again.

Place the roll seam side down and slice it with a string of floss. Mark the dough with roughly equal sizes across the roll, then place the floss string underneath the roll, making sure there is enough overhang on both sides. Bring the overhang up using both hands, then cross it across the dough roll the way you do while trying a string. (For make-ahead instructions, check the notes at the end to follow after this step)

Place the cut rolls in a baking pan, making sure to leave enough space between each roll for them to rise. Cover them lightly with cling film, and let them proof and rise for another 1.5 to 2 hours until they are doubled in size.

Once the rolls have doubled in size, preheat the oven to 160-170℃ and bake for 15-20 minutes. Don't let the buns turn golden brown, take it out while they are still a little blonde.

Once the milk comes to a boil, add half of it to the egg and sugar mixture while continuously mixing. This process is called tempering the eggs and is done so that the eggs can get used to the heat before they are added to the boiling milk on the stove, and avoid scrambling the eggs when they come in contact with high heat.

Transfer the milk and egg mixture to the saucepan and cook on low heat while continuously whisking to avoid any scrambling. Cook the custard for 3-5 minutes until it starts thickening. Take it off the heat and strain the custard it into another bowl immediately to stop the cooking process.