Preheat oven to 350 degrees F (175 degrees C). Grease a 9x13 inch baking dish.
In a large bowl, cream together the butter and brown sugar until light and fluffy. Beat in the eggs one at a time, then stir in the vanilla. Combine the flour, baking soda, cinnamon, and salt; stir into the creamed mixture until well blended. Mix in the oats until evenly distributed. Spread half of the mixture into the prepared baking dish.
In a medium saucepan over low heat, melt the caramels with the sweetened condensed milk. Pour over the oat mixture in the baking dish. Sprinkle with the chopped pecans or walnuts, and chocolate chips. Spread the remaining oat mixture over top.
Bake for 30 minutes in the preheated oven, or until the top is lightly browned.
Cool before cutting into bars.
Interesting Facts
The origin of Oatmeal Carmelitas is unknown, but the earliest known recipe dates back to 1985.
These bars are a popular potluck dish, as they are easy to make and transport.
Oatmeal Carmelitas are a popular variation of the classic oatmeal cookie.