Cream together 1 cup of butter, brown sugar, and eggs. Add the vanilla. Add 1 teaspoon salt, baking soda, and flour. Mix. Add oats and mix well. Press 2/3 of the dough into a greased cookie sheet.

Put sweetened condensed milk, chocolate chips, the remaining 1 tablespoon of butter, and 1/2 teaspoon salt into a microwave-safe bowl and microwave for 1 minute and stir. Keep cooking at 30-second increments and stirring until melted. Pour over the dough and spread out. Sprinkle the rest of the dough over the fudge.

Bake at 350 degrees for 20 minutes.