Successfully tried this today and took some hints from user infinite3186's comment thread when I make this.
Tips for making this successful again (for me):
1. Make sure butter is room temperature. It makes a difference, specially when making the choux part because you need the butter to melt before the milk boils. If you don't have room temp butter, just soften it in the microwave before putting it in.
2. I used 2 eggs instead of 3. I read comments that some people only used 2 or some used 3. So make sure to start small (i.e. 2 eggs, beaten) and pour in small amount to mix before it gets to the correct consistency. Heck, I didn't even used 2 full eggs. Think it was 1.5 for me. So it definitely varies.
2 a. Make sure to really spread the choux dough out for a minute or so before putting the eggs in.
3. The cookie dough melts really fast once you take it out of the fridge. It was hard trying to get it out of the dough after cutting it into perfect circles. I ended up putting ice bricks underneath the dough so it comes out in one piece, frozen.
Another method I saw is to roll the dough into a log, freeze it and then cut it into discs.
4. Watch the video entirely before you make it. I somehow skipped the part about leaving the puffs in the oven (door ajar) for 10 minutes. Nothing major happened, I just shoved it back into the oven after I took it out for a minute. Also make sure it's in the oven for the full 30 minutes. Don't open the oven door when it's not 30 minutes yet!
5. I spent 3 hours on this recipe and only made 6. And I have left over cream. Was it worth it? It was fun and nice experience. You definitely get into a motion of what you need to do next. And Mum loved it. You know it's good when an Asian parent likes the dessert!

에어프라이기로 하시는 분들은 190도 10분 예열하고 170도 18분구우면 딱 이쁘게 잘 구워져요!!

I like how quiet the video is. no music . no talking . just utensil sounds

수상할 정도로 베이킹을 잘하는 요리 유투버 ㄷㄷ

Just tested this today, too bad the result isn't quite satisfying 🥲 Additional tips for those who haven't tried making choux (the puff) before, do not use medium/high flame when cooking the milk and butter before adding the flour, use only low flame and keep evaporation to a minimum else you might end up with a clumping piece of starchy dough which can't be used, I had to discard the first batch after that mistake! Another easier method I saw was to cook the butter and flour first, then add in the milk and water, which worked much better for me.

Then the other problem, don't mix in too much egg to the cooled dough, if it's too watery the choux won't rise! I didn't even use 2 full eggs and mine was a bit runny.

Although this recipe looks easy but it definitely requires attention to it's minor details, so it isn't quite easy for some beginners who have no experience with making choux, better luck for those who want to try making.

실패 없는 쿠키슈 레시피라면서요 ㅠㅠㅠㅠㅠㅠㅠ

I've tried so many recipes and this is the best one. Everyone at home loved them and said they were the best I've ever made. Thank you!

В руках мастера все выглядит просто и быстро, но когда сам готовишь, то получается долго и трудоемко! 🍮😱

생각보다 시간이 오래걸리긴 했지만 너무 맛있게 잘 구워졌습니다! 그리고 오븐엔 190도에 25분 예열후 190도에 15분 170도에 15분 구웠습니다!! 좋은 레시피 너무 감사드려요💗

슈 부풀어오른 거 보고 진심으로 와!! 했다 ㄷㄷㄷㄷ

Woah, the tip about using a small cup to make a guide for where the dough goes is BRILLAINT!

너무 잘돼서 진심으로 와!! 했다 ㄷㄷㄷ
왁ㅋㅋㅋ이거야이거지~~ 요금제 비싸서 고민했었는데 시월모바일 알뜰폰요금제는 왤케쌈 당장 바로 갈아탐 ㅋㅋㅋ

Ой,ну слушайте,так интересно наблюдать как все делается...а звуки естественные просто дополняют видео ...никакой лишней болтовни и музыки фоном.Благодарю ,Автор,наверное очень вкусные получились

Это пытка смотреть на такую красоту, при невозможности попробовать! Хочу пирожное!!!

Obsessed with this! No talking, no music, just straight to the point. So satisfying to watch. Perfect execution!😘😘😘😘

обожаю каналы у корейцев с рукотворным трудом, будто бы готовка, или создание игрушек. Вроде ничего особенного, готовка есть готовка, но так затягивает.... Я кстати заметила, что только у корейцев выходит передать эту спокойную атмосферу в таких вещах, на русских каналах та же готовка - это суета и шум. Спасибо за ваш канал))

This turned out perfect! a small tip for anyone making this, at the start, start with 1 egg when adding it to the dough instead of 3 as shown in the video. if it isnt liquid use 2 eggs. Just be mindful of teh measurements.

According to the proportions given by the author, the blanks did not work out. The  custard dough is liquid !!! And this one is this option from the professionals -
Сustard dough:
• Milk - 47 gr.
• Water - 47 gr.
• Butter - 48 gr.
• Salt – 1.2 g.
• Eggs – 167 g (3 pcs.)
• Flour – 97 gr.
1) Mix the eggs well. Set aside.
2) Place butter, milk, water and salt in a saucepan.
Heat to a boil.
3) Stirring constantly, gradually add flour.
4) Brew the dough for 5 to 10 MINUTES
5) Turn on the stove.
6) Let the dough cool to 65 degrees.
7) Add mixed eggs.
8) Knead the dough for 15 minutes.

Один из тех рецептов, от приготовления которого трудно оторвать взгляд, но который сам никогда готовить не будешь))

Если Вы живёте в такой же гармонии как готовите значит жизнь удалась!!Будьте счастливы!!Привет из Питера!!!!