Beat eggs in a medium size bowl. Add the sugar, cornstarch, cinnamon and apple butter. Mix well.
Add milk and whisk together.
Press the pastry into a 9" pie plate that has been sprayed with cooking spray.
Pour the filling into the unbaked pie crust. Use a spoon to mix the filling once it is in the crust to be sure all of the ingredients are equally distributed.
Bake at 375 for 60-65 minutes, or until the center is set. It will still seem slightly "jiggly" in the very center, but a knife put in the center should come out nearly clean.
Cool in the pie plate on a wire rack. Do not slice into the pie right away, as it will continue to set as it sits.
Store the pie in the refrigerator once it is cooled.
*It's best to use a high fat milk for this recipe. You can even use evaporated milk or half and half.*I would start checking to see if the pie is done after 55 minutes of baking. *If the edge of the crust is getting too brown, cover it with foil.The calories shown are based on the pie being cut into 8 pieces, with 1 serving being 1 slice of pie. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate. **We are not dietitians and recommend you seek a nutritionist for exact nutritional information.**