Pineapple Buns with Custard Filling (菠萝包)

Ingredients:

For making bun

   Ingredients and the recipe is here.

For Custard Fillings

• 2 Large Eggs
• 75 g Sweet Cream Butter or Unsalted Butter
• 3 Tsp or 120 g Condensed Milk
• 3 Tsp Sugar -adjust it to your taste
• 1/4 tsp Salt
• 1/3 cup + 2 Tsp or 50 g Con Starch
• 1/2 can Evaporated Milk
• 3-4 drops Yellow Food Gel Coloring (optional)

For Pineapple Topping Dough

• 1 Large Egg
• 1 tsp Vanilla Extract
• 145 g Sweet Cream Butter or Unsalted Butter
• 100 g Confectioner Sugar
• 1 tsp Baking Soda
• 220 Bread Flour

Preparation:

For making bun

   Ingredients and the recipe is same as here.

For Custard Fillings

1. Microwave to melt butter and set it aside to bring it back to the room temperature.
2. Beat eggs thoroughly.
3. Add condensed milk to the beaten egg and whisk thoroughly.  
4. Add sugar, salt  and melted butter to the mixture and whisk them thoroughly to combine them.
5. Pour in cornstarch and continue whisk it.
6. On a stove, boil the water in a sauce pan on medium high heat.  When the water gets boiled, put the custard mixture bowl on the sauce pan.  Reduce the heat to medium low and stirring the mixture constantly until it gets thicken.  When you see the butter coming out of the mixture, remove it from the stove top.
7. Discard water from the sauce pan.  Turn it back on the stove to medium heat.  Pour back in the custard mixture together with evaporated milk.  Reduce the heat to the low and continue cooking the mixture until they are well combined.  This process will take about 3-4 minutes.  
8. When done, transfer the custard into a bowl and let cool.  When it is cool down, cover it with the plastic wrap and refrigerate for a couple of hours.

For Pineapple Toppings

1. Microwave the butter to melt and set it aside.
2. In a mixing bowl, beat the egg.  
3. Add vanilla extract to it and whisk them together.
4. Add the melted butter and stir the mixture
5. Add confectioner sugar and mix it.  Don't worry if there are some lumps.
6. Mix baking soda and the bread flour in a separate bowl and stir them well.  
7. Add flour and baking soda to the other mixing bowl.  Whisk them together well.  After whisking them for a while, use spatula to combine them very well.  
8. When you see the shiny dough and everything well combined, it's done.  Cover the bowl with the plastic wrap and refrigerate for at least 15 minutes.

Putting Everything Together:

1. Cut the dough into 16 equal pieces, each weigh about 72 g.  Make each of them a ball shape.  Cover them with the plastic wrap.  Set them proof for 20 minutes.
2. Get custard out of the refrigerator.  Make 16 equal balls.  They will be sticky. Wear the disposable plastic gloves or rub your hands with oil while making the ball whenever it gets sticky to your hands.
3. Set aside a bowl with about 1/2 cup of of all-purpose flour.
4. For each dough ball, flatten it with the palm.  Then use the rolling pin to get about 2.5 inch diameter.  Put a custard ball in the middle. Wrap the dough and pinch them together and seal the top.  Make it a round ball.  Dip the bottom into the flour.  This is to prevent the bottom from sticking to the resting surface later.  Repeat this for the remaining dough.
5. Cover all of them with the same plastic wrap that was used before.  Let them sit for another 45 minutes or when they reach to its doubled size.
6. Get the pineapple topping out of the fridge.  The longer you let the pineapple dough sit in the fridge, the more harder it will be and it'll be a bit hard to remove it from the bowl.  Divide it into two equal pieces.  For each piece, using the hand to make two rolls.  Each roll should have about 1.5 inch diameter wide and the equal length (about 10-inch or so).  
7. Cut each roll into 8 equal pieces.  You should have 16 pieces altogether. 
8. Lay a plastic wrap (at least 12x12 inch size) on the cutting board/kneading surface (I use silicone cutting board underneath, or you can use any kneading surface you want).  Place a piece of pineapple topping at the one third position of the plastic wrap.  Fold the plastic wrap to half and it should cover the pineapple piece.  Use the rolling pin to gently roll the pineapple topping dough into the round flatten shape.  It should be about 3.5 to 4 inch diameter. The goal is that it should be big enough to cover up the entire bun except its bottom. 
9. Preheat the oven to 375 F degree.
10. Place the pineapple topping on top of the bun like a cap.  Its side will hang on the side.  It's okay and you don't necessarily have to make them stick to the side.  During the baking process, they should automatically stick to the bun by themselves.  Repeat this process for the remaining buns.
11. On a non-stick baking tray (mine is 11 x 17), lay a parchment paper.  Transfer buns onto it.  Each try holds 8 of them and I need two baking trays.
12. Prepare the egg wash by beating an egg and add 1 Tsp of water.  
13. Brush the top of each bun with the egg wash.  
14. Bake them for about 14-17 minutes.  
15. Remove from the oven and serve.

Note: During the baking process, the pineapple topping (the cookie dough will crack).  This resembles the pineapple once done and thus its name.