Peanut butter ice cream

The recipe for the ice cream came from The Ice Cream Maker Companion by Avner Laskin

Peanut Butter Ice Cream
Makes 15 balls (whatever that means)
1 1/2 cups whole milk
1/2 cup whipping cream
1 vanilla bean, split in half lengthwise
2/3 cup sugar
6 egg yolks
1/2 cup smooth natural peanut butter

1. In a saucepan, bring the milk, cream, vanilla bean, and half of the sugar to the scalding point over medium heat.
2. In a bowl, beat the egg yolks and the remaining sugar with a wire whisk until smooth and uniform.
3. When the mixture in the saucepan begins to foam, reduce the heat and quickly stir in the yolk mixture. Remove the vanilla bean and scrape the seeds back into the saucepan.
4. Using a wooden spoon, stir the custard constantly and cook over low heat until it reaches 175 degrees.
5. Remove immediately from the heat and continue stirring, so that the custard does not overcook.
6. Pour the custard into a clean bowl through a fine mesh strainer, so that the liquid is smooth and lump-free.
7. While the custard is still warm, add the peanut butter and mix well. It is important to do this while the custard is warm so that the flavors are fully absorbed.
8. Cover the custard with plastic wrap and let cool slightly, then place in the refrigerator for at least 4 hours, until very cold.
9. Transfer the cold custard to the bowl of your ice cream maker and process according to the manufacturer's instructions.

Now, I still don't understand the 15 ball serving, but I can tell you this, it isn't very much. I could very easily have fit a double recipe in my small ice cream maker, if not more. There was barely enough for the five of us, and nobody got a bowl full. Thank heaven I'd made hot fudge and whipped cream to make up for the tiny portions.
Oh, and I'm too poor to have vanilla beans sitting around the house so I just used vanilla.