Peel and slice 5-10 apples, or however many you want. Any filling you have left over you can freeze, so don't worry about having too many apples. Use Gala or Winesap (mom's favorites).
Spread apple slices on a piece of screen wire (or a drying rack) and put them outside in the sunshine to dry. You want the air to be able to get through and dry them. If you don't have handy screen wire laying around or a drying rack, you can place the apples on a cookie sheet but it will take them longer to dry.
Once apple slices have dried out, take them back inside and place them in a pan with about an inch of water.
Cook apple slices on low heat until tender.
Add sugar and cinnamon to taste.
Next, mix the first 3 ingredients (flour, milk, and oil) to make the dough (your crust).
Use a rolling pin to roll out the dough.
Use your hands to separate the dough into medium sized circles (about 4-5 inches across). You want each circle large enough to fold over after adding the filling.
Add about two large tablespoons of your cooked apple filling onto the middle of each circle of dough.
Fold one side of the circle over the filling and to the other side. Pinch the edges together all the way around the side you folded together so the filling will not fall out during frying.
Continue until you have all the apple jacks folded over filling and ready to fry.
Put a large spoonful of Crisco solid shortening in a frying pan on medium heat.
When the grease is hot, place 2 or 3 jacks in the pan. DO NOT CROWD the jacks.
Fry for about 3 minutes on each side until golden brown.
Remove from the pan, let them cool a bit, and then enjoy as soon as possible!