Prepare walnuts by placing them on a baking sheet in an even layer. Place in oven and toast 8-10 minutes until fragrant and browned. Remove from oven and cool. Chop into small pieces and set aside.
Combine the butter and sugar.
Add the salt, vanilla, cinnamon, and nutmeg.
Whisk in the eggs, milk, coconut, oatmeal, and walnuts.
Pour the filling into a prepared 9-inch pie shell and bake in the preheated oven until the edges are set and the middle jiggles slightly, 40-60 minutes. The crust may brown quicker than the pie. After 35 minutes, start checking the crust. Usually, the crust needs to be covered for the remaining bake time.
Remove from oven and let cool for at least 4 hours.
This is best served with freshly whipped cream: 1 cup heavy cream, 1 tablespoon sugar, and ½ teaspoon vanilla. Whip until soft peaks and pile high on each piece of pie!