In the bowl of a stand mixer fitted with the whisk attachment combine flour, sugar, salt and butter.
On low speed, mix until mixture is crumbly.
Slowly add in cold water with the mixer on low.
When the dough becomes to come together, turn the mixer off and knead with your hands, just until combined.
Shape into a rectangle, cover with plastic wrap and refrigerate for 30 mins.
While dough is chilling, prepare your pumpkin butter.
Add all ingredients to a stand mixer, fitted with the paddle attachment.
Beat until light and fluffy.
Pour on a piece of parchment and spread flat. Wrap in parchment and refrigerate.
Once chilled, roll dough into a rectangle about 1/2 inch thick on a lightly floured service. Once dough is in a rectangle, Place chilled pumpkin butter in the middle on top of dough.
Fold one side into the middle, and the other side over that, like a letter. Repeat this process 4 times.
You should see the layer of pumpkin butter start to almost come through the dough.
Fold into one last letter fold, cover with plastic wrap and chill.
Place all ingredients, except for the flour in a saucepan over medium heat. Cover with a lid and allow to boil.
Once boiling, turn to low and allow the filling to cook down.
When the apple pieces are soft, vigorously mix in the flour to absorb the liquid. Make sure there are no pieces of flour left. Set aside.
Roll out dough to a rectangle about 6 by 12 inches. Slice into 6 sections for large pastries or 10 for smaller pastries. ( I based the timing on 6 pastries) Heat oven to 400F.
Roll out each section of dough to about a 4 inch by 4 inch square. Place a large spoonful of filling in the center. Paint the edges with egg wash and diagonally close the seams. Use a fork to ensure they are sealed and to make it look prettier. Repeat until all of the pastries are done. Set aside on parchment.
Place pastries on a cookie sheet lines with parchment. Poke a few air holes on the top of each pastry. Paint with egg wash and sprinkle on cinnamon and sugar.
Bake for 25-30 minutes. The pastries are done when they look slightly puffed and golden brown.
Remove from oven and cool on a cooling rack.