In a small bowl, dissolve coffee granules in hot water. In a large bowl, combine the egg white, 3/4 cup sugar, oil, corn syrup, vanilla and coffee; beat until well blended. Combine the flour, cocoa and salt; gradually add to coffee mixture and mix well.
Roll into 1-in. balls. Place 2 in. apart on ungreased baking sheets. Flatten to 1/4-in. thickness with a glass dipped in the remaining sugar.
Bake at 350° for 5-7 minutes or until center is set. Remove to wire racks to cool. Store in an airtight container.