1. Pulse first 5 ingredients in a food processor 3 or 4 times or until combined. Add butter and 1/4 cup pecans; pulse 4 or 5 times or until pecans are ground.
2. Transfer mixture to a bowl; stir in remaining 1/4 cup chopped pecans with your hands, mixing and squeezing to form larger pieces. Cover and chill until ready to use.