Whisk together the milk, cream, sugar, egg yolks, cornstarch, corn syrup, and salt.
1 ¾ cups whole milk, 1 ¼ cups heavy cream, 2 egg yolks, ¾ cup dark brown sugar, 1 ½ tablespoons cornstarch, 2 tablespoons light corn syrup, ½ teaspoon kosher salt
Place over medium-high heat, stirring occasionally until the mixture starts to steam. Continue to whisk and bring the mixture to a boil. When boiling throughout, remove from heat. Pass through a strainer if needed.
1 ½ teaspoons vanilla extract, 2 cups mashed ripe bananas
Cool off slightly, 5-8 minutes.
Pour into an airtight container and chill for 8-10 hours.
To freeze, remove it from the refrigerator and pour it into the ice cream freezer. Follow the directions with your freezer; each one can vary. My KitchenAid stand mixer (affiliate link) with ice cream maker attachment(affiliate link) takes about 20-25 minutes to freeze fully.
When finished, transfer to an airtight container and place in a deep freeze for an additional 4-6 hours until hardened.