For the Infused Milk: Crush and toast the macadamia nuts in a 176°C / 350°F oven until the nuts begin to have a toasted aroma. Bring the milk to a simmer and add the nuts to the hot milk when they come out of the oven. Steep the milk for 30 minutes, strain the nuts out and weigh the required amount of milk.
For the Ice Cream Base: Make the ice cream base according to the Classic Ice Cream Method.
Strain the base through a fine-mesh strainer and cool over an ice bath. Age the base under refrigeration overnight.
Once the base has aged, churn to the desired consistency.
Harden for at least 2 hours and up to 4 hours. Reserve until needed.