In a large mixing bowl, beat the butter with an electric mixer until creamy. Gradually beat in the granulated sugar and brown sugar. Beat in the eggs and vanilla. Set aside.
In a separate medium mixing bowl, combine the flour, baking soda, cocoa, and salt. Gradually add the flour mixture to butter mixture, beating well to combine. Cover and chill at least 2 hours or overnight.
Preheat oven to 375 degrees F. Line a large baking sheet with parchment paper or coat with nonstick cooking spray.
Combine the nuts with the 1 tablespoon sugar in a small bowl.
Divide the dough evenly into 4 parts. Work with one part at a time, leaving the remainder in the refrigerator until needed. Divide the first ¼ of the dough into 12 pieces. Roll a piece of dough into a ball and then flatten slightly. Place a piece of candy in the center and roll it into a ball, enclosing the candy inside. Press the ball into the sugar/nut mixture to coat the top. Transfer to the prepared baking sheet and repeat with remaining cookie dough and candy, placing the cookies about 2-inches apart to fill your baking sheet.
Bake for 8 minutes in the preheated oven. Allow to cool for 3 to 4 minutes on the baking sheet before transferring to a wire rack to cool completely. Repeat with remaining refrigerated dough.