Prepare the custard:

1. Beat eggs and sugar in a medium bowl until thick and pale yellow.
2. Heat milk in a small saucepan over medium heat until hot but not boiling.
3. Gradually whisk the hot milk into the egg mixture in small additions. (Adding the milk too quickly may cause the eggs to scramble.) Once thoroughly mixed, return the mixture to the saucepan.
4. Heat saucepan over medium-low heat and cook the custard, stirring constantly with a wooden spoon until it is thick enough to coat the back of a spoon, about 5-8 minutes.
5. Remove saucepan from heat and stir in ½ cup of the peanut butter.
6. Strain custard through a fine mesh sieve into a large bowl.
7. Allow the custard to cool for several minutes, stirring often.
8. Stir in cream and vanilla.
9. Cover and refrigerate until cold, 6–8 hours.

Make the Ice Cream:

1. Process the custard mixture in an ice cream maker according to manufacturer's directions. Transfer to a bowl, quickly swirl in the chopped nuts and remaining ½ cup peanut butter. Cover, and freeze until hard.
2. Enjoy!