Preheat your oven to 350°F (175°C).
Line a 9x13 inch baking pan with parchment paper, allowing some overhang.
In a large mixing bowl, combine the flour, oats, light brown sugar, baking soda, and salt. Stir until well mixed.
Pour the melted butter into the dry ingredients. Use a spatula to combine until the mixture resembles a crumbly dough.
Scoop out about 1 cup of the mixture and set it aside.
Press the remaining mixture evenly into the bottom of the prepared baking pan.
In a double boiler or microwave-safe bowl, combine the unwrapped caramels and evaporated milk. Heat gently until melted and creamy.
Pour the melted caramel mixture over the crust in the baking pan, spreading it evenly.
Sprinkle the chocolate chips evenly over the caramel layer.
Crumble the reserved mixture over the chocolate chips.
Bake for 25-30 minutes, or until the topping is golden brown and the caramel is bubbly.
Allow the bars to cool for at least 30 minutes before lifting them out and cutting into squares.
