In a saucepan (or microwave), melt the butter. In a separate pan, toast the pecans until fragrant. Remove pecans and butter from heat to cool.
Set the oven to 350*F.
In a small bowl, mix the flour, baking soda and salt and toss together to combine. Set aside.
In a large bowl, cream the sugars and butter until incorporated and smooth/slightly matted. Add the vanilla to the creamed sugars and mix well. Add the two eggs to that mixture and blend well.
Take the flour mixture that you set aside earlier and add it to the wet ingredients all at once and blend well. From there, add the rolled oats to the wet ingredients and fold until all the oats look covered. Add the chopped cooled pecans and the chopped heath bar and mix until everything looks well distributed in the mix.
Drop the mix by heaping table spoon fulls onto parchment paper and bake for 9-12 minutes.