In a medium saucepan, combine the heavy whipping cream, sugar, cinnamon, and nutmeg. Heat over medium-low heat, whisking occasionally, until the sugar dissolves and small bubbles form around the edges. Remove from heat and let sit for about 5 minutes.

In a separate bowl, whisk together the egg yolks, Ponche de Crème, and sweetened condensed milk until smooth.

Slowly add a little of the warm cream mixture to the egg mixture, whisking constantly. Continue adding the warm cream gradually until combined.

Return the mixture to the saucepan over medium-low heat. Stir constantly, scraping the bottom and sides, for approximately 8–12 minutes, until the custard coats the back of a spoon and reaches 170–175°F. Do not boil.

Remove from heat and pour through a fine-mesh strainer into a clean, shallow, heat-safe container.

Refrigerate promptly, loosely covered if still steaming, then cover securely once cooled. Chill for at least 4 hours or overnight until completely cold.

Pour the chilled custard into your prepared ice cream maker and churn according to the manufacturer's instructions, about 20 minutes, until thick and creamy.

Transfer to a freezer-safe ice cream container, cover tightly, and freeze for at least 6 hours or overnight before serving.