Preheat oven to 350 degrees. Grease cookie sheet.
In a small bowl, beat margarine until creamy.
Add and blend in brown sugar and 3 tablespoons sugar.
Add egg, baking soda, corn syrup and vanilla; beat.
In another small bowl stir together flour and cocoa powder and mix with margarine mixture. If batter becomes very stiff, use a wooden spoon to stir in flour.
Cover mix and refrigerate until batter is firm enough to shape.
Shape dough into 40 (1 inch) balls.
In another small bowl, mix the 1/4 cup of remaining sugar with cinnamon.
Roll balls into cinnamon mixture and place 2 inches apart on prepared cookie sheet.
Cool and remove from cookie sheet.