Preheat the oven to 350F.
Brush a 7"x11" baking pan with melted butter. Line with non-stick paper and brush the paper with melted butter as well.
In a bowl, stir together the flour, salt, baking soda, sugar, oats, nuts and chocolate. Pour in the melted butter and stir until blended.
Lightly press the mixture into the prepared pan.
Drizzle the caramel on top.
Bake at 350F for 25 to 30 minutes or until lightly browned and the caramel is bubbly
Cool to room temperature without removing from the pan before cutting into squares or bars.