Note – If you are using a canister ice cream maker like I have listed below, ensure that it has frozen for at least 24 hours prior to making your ice cream to ensure it is solid. 48 hours is better. 

Roasted Bananas 

1. Preheat oven to 325 degrees. Place peeled bananas into a non-stick sprayed baking dish. Sprinkle with brown sugar, or honey, and 1 tablespoon of butter. Bake until roasted through, about 25-30 minutes. Check to ensure that butter and sugar to not burn. Set aside and allow to cool completely, or overnight in the fridge.
2. Once cool you can mash them, or for a more smooth feeling, you can blitz them in a food processor until smooth. 

Ice Cream Base

1. In a large saucepan, preferably one with a rounded bottom, add in the heavy cream and half and half, corn syrup, salt and vanilla. Bring to a light simmer over medium low heat, stirring frequently.
2. As the milk steams, in a medium bowl, whisk together the sugar and the egg yolks. Whisk until they are light and fluffy and the sugar has dissolved, about 3 minutes. Set aside.
3. Temper the cream into the egg yolk mixture by constantly whisking the eggs as you slowly pour one cup of the steaming cream mixture into the egg yolks to bring them up to temperature. Repeat with a second cup of steaming cream.
4. Once the eggs are tempered, pour the whole mixture back into the saucepan. Bring the pan back to temperature and bring it up to 180 degrees when measured with an instant read thermometer. Ensure that you are stirring constantly to avoid scrambling the eggs.
5. Here, add in the smooth banana purée. Stir to combine completely
6. Place a large bowl with a wire mesh sieve over the bowl and strain the ice cream base to remove any overcooked eggs or chunks of banana for a more smooth ice cream base.
7. Cover and place the bowl into the fridge overnight to chill.