Preheat oven to 350 degrees. Lightly grease cookie sheets.
In a large mixer bowl or stand mixer, beat together butter and sugars until light and creamy. Add in corn syrup and eggs, one at a time.
In a separate bowl, mix together flour, cream of tarter, cocoa, salt and soda. Add these into the butter/sugar mixture and beat on low until well mixed.
With a large wooden spoon, stir in chocolate morsels, nuts and raisins. Refrigerate dough for 30-40 minutes until firm enough to handle. Grease your hands with cooking spray.
With hands, roll the dough into golf ball sized balls and roll them in reserved sugar. Place on baking sheet and flatten slightly with a glass. If the glass sticks, try moistening with water and dipping the glass into sugar before flattening.
Bake for 15 minutes until lightly browned around edges and crackly on top. Cool on cookie racks. Store in sealed containers.