Simmer and Reduce the Maple Syrup: Pour the maple syrup into a sturdy medium saucepan. Set over medium-high heat and bring it to a lively simmer. Let it boil gently for 3 to 4 minutes, stirring occasionally, until the syrup thickens slightly and reduces to about ¾ cup. This step intensifies the maple flavor.
Incorporate the Creams and Salt: Lower the heat to medium and slowly pour in the heavy cream, light cream (or evaporated milk), and a pinch of salt. Stir the mixture often as it heats back up, then remove it from the heat just before it reaches a boil.
Temper the Eggs Gently: In a mixing bowl, whisk the eggs until fully blended. To prevent curdling, slowly drizzle in about ⅓ to ½ of the warm cream mixture, whisking constantly. This brings the eggs up to temperature gradually.
Cook the Custard Base: Return the tempered egg mixture to the saucepan with the remaining cream. Place it over low heat and cook gently, whisking the entire time. Watch for it to thicken slightly without boiling—aim for a silky texture and a temperature around 175–180°F, if using a thermometer.
Strain and Chill Completely: Pour the custard through a fine mesh strainer into a clean bowl to remove any bits of cooked egg. Cover with plastic wrap, pressing it gently against the surface to prevent a skin from forming. Refrigerate for at least 3–4 hours, or until completely cold.
Churn the Ice Cream: Pour the chilled custard into your ice cream machine and churn according to the manufacturer’s instructions. When the mixture starts to thicken but is still soft, add in the chopped walnuts and maple flakes (if using). Continue churning until fully frozen and creamy.
Freeze for Firmer Texture: Transfer the ice cream to a freezer-safe container. Press a piece of parchment or wax paper over the top before sealing with a lid. Freeze for at least 2–3 hours or until firm enough to scoop.
Serve and Garnish: Scoop into bowls or cones, and top with additional walnuts or maple flakes if desired. Serve alongside warm apple desserts or enjoy it all on its own.