In a large saucepan, bring the cider and sugar to a boil. Cook, stirring occasionally until reduced to 3 ounces, roughly 25 minutes (pour into a heatproof measuring cup to check). Remove from the heat and whisk in the milk, cream, and cinnamon.
In a small bowl, whisk together the egg yolks. Slowly whisk in some of the hot cider mixture to temper the eggs. Pour the egg mixture back into the pan.
Return to the saucepan and bring back to a boil, whisking often. Cook until it thickens and coats the back of a spoon.
Strain the mixture into a heatproof bowl. Place the bowl in an ice bath and cool to room temperature. Remove from the ice bath and chill in the refrigerator until cold. Fold in the PDCC Pumpkin Seeds and Donut Pieces
Follow the directions on your ice cream maker to freeze. If you are freezing by hand, place the mixture in a covered bowl in the freezer. Whisk the mixture every 30 minutes or so for a few hours until the mixture is frozen solid.