Prep Dough: In bowl of electric mixer, cream butter and two sugars until light and fluffy. Add vanilla, then eggs, one at a time, and mix well. Add cocoa and mix again.
Prep Dry Ingredients: Sift together flour, baking soda and salt and add to dough. Mix on low speed until just combined. Gently fold in chopped white chocolate, oats and pecans.
Bake Cookies: Line baking sheet with parchment paper. Use a 1 3/4" ice cream scoop or a rounded tablespoon to form cookies and place on baking sheet. Use your hands to flatten dough slightly. Bake for exactly 15 minutes (cookies may seem slightly underdone). Remove from oven and cool for a few minutes. Transfer to wire baking rack to cool completely.