Instead of having chunks of peanut butter mixed into a vanilla base (like this), I combined my peanut butter with the hot cream mixture so that the base is smooth, creamy, and peanutty through and through. I used Jeni Britton's no-egg technique (as I do for almost all of my ice creams now).
One mistake I made that you shouldn't: I left my bananas out on the counter, and when I added in the chunks, they lowered the temperature of the churned ice cream, making it more soupy. So when I put it in the freezer, it lost a bit of its smooth texture as it hardened. Freeze (or at least chill) your banana pieces beforehand!
Peanut Butter Ice Cream with Banana Chunks
makes about one quart
1 ounce cream cheese, softened
1/3 cup natural peanut butter
1 tablespoon plus 1 teaspoon corn starch
3 1/2 cups half and half
2/3 cup sugar
1 1/2 tablespoons corn syrup
1 teaspoon vanilla
2 ripe bananas, cut into small chunks and frozen or chilled
1/2 cup roasted, unsalted peanuts*
In the bottom of a medium bowl, whisk the cream cheese and peanut butter until smooth. Set aside. Prepare an ice bath in a larger bowl.
In a small bowl, whisk together the cornstarch and 2 tablespoons of the half and half, making sure the cornstarch is dissolved. Pour the rest of the half and half into a large pot and whisk in the sugar and corn syrup. Bring to a boil over medium-high heat, and then simmer, stirring frequently, for 4 minutes.
Remove from heat and whisk in the cornstarch mixture. Return the pot to medium-high heat, bring back to a boil, and cook for 1 more minute, stirring or whisking constantly, until the mixture is slightly thickened.
Pour the milk mixture into the bowl with the cream cheese and peanut butter and whisk until everything is combined and smooth. Add the salt and vanilla. (While it's still warm, taste and decide if you'd like to add more peanut butter for a stronger flavor.) Set the bowl into the ice bath and cool, stirring every few minutes, until the liquid is thoroughly chilled. This should take about 25 minutes. It's even better if you can refrigerate it for several hours or overnight, but it should freeze fine after the ice bath if it's completely cool.
Freeze in an ice cream maker, adding the banana chunks and peanuts at the very end. Transfer the ice cream to a container and freeze for several hours until firm.
*This is what I had on hand, but I bet salted peanuts would be really good, too.
(Image: Elizabeth Passarella)