Dilute cocoa with hot water and oil.

In a separate bowl, mix next five ingredients to form dough. Add cocoa mixture to dough and mix for five seconds, just long enough to marbleize. Divide dough into four.

Place on wax paper and roll into logs about 20 inches long; freeze for two to three hours.

Slice each log into one-inch wide slices. Place cookies on cookie sheet, leaving space between them, as they will expand. Bake for 12 minutes at 350 degrees Fahrenheit.

Melt chocolate (microwave for one and a half minutes) and margarine. Add corn syrup and pareve milk; mix.

Using a teaspoon, drop a small dollop of the mixture onto the center of each cookie.