1. Preheat the oven to 180 degrees Celsius.

2. Brush a medium sized baking tray with margarine and lightly sprinkle with flour.

3. Melt the butter with the chocolate in a small saucepan. Do not let it boil.

4. Remove the saucepan from the heat and let it cool down a little.

5. Beat the eggs with the sugar until smooth.

6. Slowly add the chocolate and rum and mix well.

7. Add the Quaker oats and chestnuts and mix with a large ladle.

8. Spread the mixture on the tray, place in the middle of the oven and bake for 30 minutes.

9. Can be served with ice cream.