Add the butter in the bowl then add the sifted icing sugar. Mix until it's smooth but not very fluffy. After that, add the egg and mix it all together thoroughly. Add in the vanilla extract if you want to, mixing it together again. Finally, add the flour in two to three different parts, icing it all together until it is slightly crumbly.
Knead the flour mixture with the tips of your fingers until it takes the form of dough. Wrap it in parchment paper and let it chill in the fridge for about half an hour to lessen the stickiness of the dough and make it easier to form later on.
Prepare the mold by spraying it with non-stick spray. Sprinkle some flour around the molds. You can also use butter instead of non-stick spray.
Divide the dough into small portions (20 grams per piece). Flatten the dough with a plate or bowl. Line the dough on the mold evenly, without any air pockets. Remove any excess dough.
Put the molds on the baking sheet, lining it with parchment paper and adding beans or rice to weigh the paper down. Allow the oven to reach 355 degrees Fahrenheit before placing it in the oven. Allow it to bake for five to seven minutes or until the dough is dry, slightly firm, and dark yellow.
Remove it from the oven and cool. Letting it bake beforehand makes it crunchy. While letting it cool, it's time to make the filling.
Mix the eggs and sugar until the sugar dissolves. Add the whipping cream and milk together. Add the vanilla extract as well, whisking it all together.
Pass the mixture through a sieve to remove any lumps then pour it into the crust. Let it bake at 300 degrees Fahrenheit for 20 minutes. Take it out once the egg puffs begin to swell a bit.
Let it cool for ten minutes before taking it out from the mold. Serve and enjoy!
Recipe by Jellibean Journals at https://jellibeanjournals.com/hong-kong-egg-tart/