Preheat oven to 175 degrees C. Prepare a 9" pan by greasing with butter or spraying it on the bottom and sides.

Melt butter and add the crushed biscuit and coffee. Mix well until it resembles wet sand. Then put mixture into the greased pan and press in the bottom of the pan and coming up about 1/2" on the sides. Place in the oven for 5-10 mins. Do not brown for long. Keep aside to cool.

In a mixing bowl beat the cream cheese and sugar together until just combined with an electric mixer on low. Add the sour cream, vanilla essence, salt and coffee. Beat again until just combined. Taste to see if the coffee flavor comes through if not add more coffee tablespoon by tablespoon and check sugar levels.

Once satisfied with the flavor, add the eggs one at a time with the electric mixer on low until just blended.

Pour half the mixture into the pan with the crust. Then layer with the oatmeal biscuits dipped in some coffee and pour the rest of the mixture over the top. Bake in a water bath to help prevent cracking.

To do this, wrap aluminum foil around the bottom of the outside of the pan, coming up about halfway up the sides. Put the pan in a large baking tray, then add hot water from a kettle to come about 1" up the sides of the foil.

Check the water bath while baking the cheesecake. Bake the cheesecake for 20-30 mins or until the center is almost set, but not quite. Constantly check after 15 minutes. There should be about 2" ring in the center that is still a bit wobbly- it will continue to cook after it is removed from the oven.

Once completely cooled, place in the fridge for 3 hours. Then dust powdered biscuit over the top to decorate. Cool in the fridge once again and serve cold.