Preheat the oven to 350 degrees
With a hand mixer, combine the butter and both sugars for about 1 minute until everything is incorporated.
Add the egg, oil, and vanilla, and continue to beat with a hand mixer until creamy, about 2 minutes.
In a separate medium-sized bowl, add the two flours, cocoa powder and salt, if using. Use a hand whisk or fork to combine the dry ingredients.
Add the flour mixture to the butter mixture and beat for a minute or so longer, just until the ingredients are well combined. Stir in the two chocolates and toasted pecans and mix well.
Refrigerate for 30 minutes or overnight.
Scoop a well- rounded tablespoon of the batter onto an ungreased baking sheet lined with parchment paper.
Bake until just set - mine are perfect at 12 minutes.
Let them sit for about 5 minutes, then transfer to a rack to cool.
Store the completely cooled cookies at room temperature in a airtight container for up to 4 days.