The Mid-Autumn Festival is one of the four most important Chinese festivals. On the evening of the 15th day of the eighth month, people would often munch on a piece of moon cake while watching the moon.

Typically, moon cakes consist of a thin layer covering salted duck egg yolks or lotus seed paste inside. In the past few decades, moon cake lovers have been finding new ways of making this pastry with varied fillings and different ways of making the crust. So before the Mid-Autumn Festival this year, I decided to learn about one of these innovations called the Ice skin mooncake.

I am currently in a classroom for making the ice skin moon cake. Before we get started, let's talk to one of the instructors for our class, Mr. Sun, to find out more about this unique pastry.

So Mr. Sun, what's the difference between the ice skin moon cake and the ones you find on the market?

"Before you make the ice skin moon cake, all of the ingredients must be cooked. The traditional moon cakes are made from raw ingredients. Maybe the filling is cooked but the crust is definitely raw. So you have to put them in the oven before you can eat them. But for ice skin moon cakes, both the outer layer and the filling are cooked before hand so you can eat them without putting them in the oven."

So who invented the ice skin moon cakes?

"The inventor of the ice skin moon cake is from Hong Kong. It was made popular by young people who want to be innovative. Because they don't have to be baked, it saves time and suits the fast-paced lifestyle that we have today."

Now we start making the ice skin moon cakes. First, we measure the ingredients. We are making a set of four moon cakes right now. As I said before, all the ingredients have been cooked before hand. The first ingredient on the scale is the baking powder.

So you need 40 grams of baking power. Then, you need 40 grams of water. Then you mix the powder with the water. Make sure there's no dry powder left and all the water is being absorbed. Then you add some buttermilk, which makes the dough smooth and oily.

As we're mixing, our instructor for today, Wang Xin, explains how the ice skin moon cake got its name.

"The reason why it's called ice skin moon cake is first, the color of the moon cake is white, the same as ice. Second, after you make it, you can put it into the fridge and wait an hour or two. So the moon cake is cold when you eat it."

After the mixing, you roll the dough into a ball and divide it into four equal pieces, 20 grams each. Then you roll them up into little balls in your hands.

Ok, now we're ready for the filling. Today, our filling is purple sweet potato. Again, we need four segments, 30 grams each.

Then, we take a ball of dough and we flatten it between our palms. Make sure that the thickness is even and it's big enough to cover the filling you just made. It can't be too thin either or the filling will leak. You may have to squeeze it a couple of times to get the desired results.

Now that it's flat, we can set the ball of filling in the middle and we pull layer of dough we just made around it. Make sure that our filling is covered from all sides. And we carefully roll it between our palms. Making the surface smooth. Don't squish it or you will break the cover and the filling will be leaked out.

The last step: you put the ball you just made on a cutting board and stamp it with a pattern. Be careful. Press on the stamp slowly until you can't push it down anymore and gently lift it up while pushing down the dough. Then, viola, your moon cake is ready to eat. And it's beautiful to look at, kind of like a white and purple marble.

That's best thing about ice skin moon cakes. No baking required.

So if you want to save time and avoid the long lines to buy moon cakes in the supermarkets this year, try making the ice skin moon cakes on your own. All you need is some simple ingredients and a passion for baking.

For Studio +, I'm Doris Wang.