Fill a large bowl with ice water and set it aside.
In a small saucepan, whisk together the egg yolks, maple
syrup, corn syrup, and bourbon until the mixture is fully combined. Do not do
this over heat.
Whisk in the milk and heavy cream.
Place the pan over medium heat. Cook, stirring constantly with a rubber spatula, until the temperature reaches 74°C to 80°C on an instant-read thermometer.
Remove the pan from the heat and pour the base into a clean
CREAMi Pint. Carefully place the container in the prepared ice water bath,
making sure the water doesn't spill into the base.
Once the base has cooled, place the storage lid on the pint
and freeze for 24 hours.
Remove the pint from the freezer and take off the lid. Place
the pint in the outer bowl of your Ninja CREAMi, install the Creamerizer Paddle
in the outer bowl lid, and lock the lid assembly onto the outer bowl. Place the
bowl assembly on the motor base, and twist the handle to the right to raise the
platform and lock it in place. Select the Ice Cream function.
Once the machine has finished processing, remove the lid
from the pint container. With a spoon, create a 11/2-inch-wide hole that
reaches the bottom of the pint. During this process, it is okay if your treat
reaches above the Max Fill line. Add the toasted walnuts to the hole in the
pint, replace the lid, and select the Mix-In function.
Once the machine has finished processing, remove the ice
cream from the pint. Serve immediately.
