There are a few ways to make apple turnovers. One is to make a pastry shell, similar to a pie crust. Another option is to make a puff pastry. Some people just use refrigerated biscuit dough. My favorite option (because I could use less butter and knew how to make it from scratch) was the pastry shell. So, here's my figured-it-out-as-I-went recipe for Apple Turnovers.
Preheat oven to 400*F
Crust:
2.5c. flour
1.5 tsp. baking powder
1 tsp. salt
Sift all dry ingredients together, then cut in 1c. butter to make coarse "crumbs". Add 6-7 T. water to make a pie-crust like dough. Put it in the refrigerator.
Filling (make while your dough is refrigerating):
4 honeycrisp apples
2T. butter
1/2 c. brown sugar
1 tsp. cinnamon
Peel and core apples, cut into slices, and half the slices lengthwise. Cook apples in butter until just tender (don't cook them all the way, they will finish in the oven). Add brown sugar and cinnamon. Then take a little flour, and use it to thicken the sauce. Go for a texture similar to ice cream topping; not too thick, but not too runny. Remove from heat.
Now take the dough out of the refrigerator, and roll it into a rectangle. I made 7 turnovers, but you can make whatever size you want. Cut the rectangle up into squares (mine were roughly 4 inch squares). It's important to make them as square as possible so you can fold them into an even triangle-this makes sealing your turnovers easier.
Once you have your squares cut, put a spoonful of filling in the center. Do just one at a time, since you will need to fold the top over and put it on your baking sheet before the warm filling melts your crust and makes it gooey. Once you have the edges sealed, use a fork to completely smoosh the edges together. (Folding your turnovers is tricky, since your filling will try to ooze out. It takes practice to figure out what works best for you, and how much filling to use per square of dough.)
Now put those turnovers on your baking sheet, about an inch apart, and bake them for 25 minutes (the time may vary based on oven types).
Enjoy the delicious pastry you've made! I would love to know if you experiment, what you do differently, and any other kinds you might make.
*Note: the filling may still leak out of your crust while baking. It came off of my baking sheet well, but you may want to bake on parchment paper if you don't want your baking sheet stained.