Preheat oven to 350°F. Line 2 cookie sheets with parchment paper.
In a small saucepan, melt the butter. Set it aside and allow to cool slightly.
In a medium bowl, combine sugars. Add melted butter and whisk until mixture is thoroughly emulsified and pulling away from the edges of the bowl, 2-3 minutes.
Add eggs and vanilla; whisk to combine.
Combine flours, baking soda, salt, and oats together in a separate bowl. Add dry ingredients to wet ingredients and fold together gently until thoroughly mixed. Fold in trail mix and chocolate.