Blanch walnuts until they lose their crunch (approximately 6-8 minutes.)
Drain walnuts. In a bowl, toss with corn syrup and powdered sugar.
Place coated walnuts in a heavy frying pan of rice oil heated to 350° F (use a candy thermometer) and stir walnuts until dark brown (approximately 3-5 minutes).
Use a slotted spoon or strainer and remove walnuts. Set out on cooling rack.
When cooled, chop walnuts in food processor. Set aside.
In a medium sized bowl lightly whisk egg yolks and set aside.
Put cream, vanilla and sugar in saucepan, whisk together and bring to a boil. When cream starts to ‘crawl up’ the pan, remove from heat and whisk hot cream into egg yolks. Be sure to whisk the egg mixture vigorously–and be sure the mixture isn’t too hot or you will end up with scrambled eggs. Set in freezer to chill.
Put butter in pan or microwave until melted and mix or whisk in brown sugar. It should have a loose texture. Set aside.
After cream cools–the cream-egg mix should be set fairly thick. Whisk in cold milk and churn in favorite ice cream machine for approximately 15 minutes. Consistency should be firm.
Fold chopped (food processor works best) caramelized walnuts and brown sugar and butter mixture into ice cream and freeze.