Almost McDonald's Apple Pie fillings

My eldest son loves McDonald's. He usually orders its fish fillet with extra tartar sauce, apple pie and ice cream. But not necessary in that combination. On one Sunday, after our lunch at a food court, he suddenly feels like having McD's ice cream and apple pie. So we went to buy. As he ate his apple pie, he raved about the fillings, the crust etc. So I told him that after we got home, I'll make him an exact McDonald's apple pie confidently.

After searching online for a copycat recipe, I realised the secret ingredients was the apple cider. As I wanted it to be quick, I used storebought puff pastry since I wanted to try out the apple pie fillings first. After my son tried the apple pie, he said he likes the crust. >_<" However, he feedback that it was more sourish. Otherwise, he thought the apple pie was nice...close, but needs some improvement. I told him I'll improve on it the next time!

Recipe for Apple Pie fillings, adapted from Babble. 
(Makes one 7" square pie)

Ingredients:
2 Apples (I used green apples), chopped to 1/2″ squares 
1/2 cup apple cider 
1/4 cup sugar 
1 teaspoon cinnamon 
zest and juice of 1 lemon 
big pinch salt 
2 tablespoons flour 

2 puff pastry sheet

Method:

1. Combine the apples, cider, sugar, zest and juice, and salt, and cook over medium heat. 

2. The mixture will bubble, and cook down. 
3. After about 15 minutes the apples will soften, but still have a little texture. Stir in the flour and cook for a minute or two more. 
4. Remove from heat and set filling aside to cool. 
5. Preheat oven to 180C.
6. Place a puff pastry sheet on a baking tray. When the filling is cooled slightly, scooped the fillings on the centre of the puff pastry.
7. Place another puff pastry to cover the fillings. Seal the sides and pierce holes on top.
8. Bake in the oven for 22mins or browned.
9. Let it cool slightly before cutting and serving.

Notes:

• The filling was a bit sour. I reckon it was due to the lemon juice and using of green apples. However, as you eat, it became better. The sourness was only during the first 2 bites.
• I reckon less flour could be use so that there is still much gravy to be seen, even though the fillings were not dry.
• Overall, the taste was very close to McDonald's apple pie filings if sweet apples were used and fillings were more wet.