Preheat oven to 350º F and line a pie dish with unbaked pie crust.
In a large bowl, stir together brown sugar, oats, sugar, and salt, then stir in milk, beaten eggs, butter and vanilla extract. Continue stirring until fully combined.
Pour mixture into pie shell, then place in oven.
Bake for 45-50 minutes, or until pie is cooked through.
Remove from oven and let cool 10-15 minutes, then serve with ice cream or whipped cream.