Preheat the oven to 350℉ and line a 9x13 baking pan with parchment paper.
Add the flour, baking soda and salt to a mixing bowl and stir well. Add the oats, brown sugar, white sugar and melted butter to the mixing bowl and mix until fully combined.
Place half of the crust into the baking pan and press down into an even layer. Bake for 10 minutes and remove from the oven.
Sprinkle the nuts evenly over the baked crust.
Next, sprinkle the chocolate chips/chunks evenly over the nuts.
Heat the caramel sauce for 15-30 seconds in the microwave to make it pourable. Pour evenly over the chocolate chips.
Crumble the remaining crust mixture on top of the caramel sauce. Return the baking pan to the oven and bake for 18-20 minutes until the top is lightly golden brown.
Allow the bars to completely cool and then chill them for 30-60 minutes before removing them from the pan and slicing.
Notes
If you want to make a smaller batch in an 8x8 pan, here are the quick conversions: