Make dough: Mix flour, sugar, and salt in a large bowl. Cut in half of the butter until mixture is crumbly. Toss in remaining butter; cut in until mixture resembles dime-size pieces. (Work quickly so everything stays cold.) Mix vinegar with about half of the water; stir into flour mixture with a fork. Mix in additional water, a little at a time, until everything becomes moist. Form into ball. Wrap in plastic and chill for at least 30 minutes.

To make filling: Sauté apples in oil for about 5 minutes or until tender. Add honey, brown sugar, and orange juice; cook for about 3 minutes. Add walnuts, raisins, currants, spices, and salt; cook about 30 seconds. Cool completely.

Preheat oven to 350°. Divide dough into two pieces. Roll one piece to 1/16- to 1/8-inch thickness. Cut into 4- to 4 1/2-inch circles. Repeat with second piece. Collect dough scraps, cover with plastic wrap, and refrigerate for at least 10 minutes.

While scrap dough cools, place about 1 tablespoon filling into middle of each already-cut circle. Wet dough edges. Fold top over filling to form a half-circle and crimp edges. Remove dough scraps from fridge, roll out, and cut more circles; top with filling and close up as described.

In a small bowl, whisk egg with water; brush over pie tops. Sprinkle with sugar, if using. Bake 20–30 minutes or until golden.