Grease a 2 pint [1 1/2 quart] mould with the oil.
Place the mould, upside down, on kitchen paper towels to drain.
In a mixing bowl, combine the nectarines, allspice, sugar, brandy and gelatine.
In a small mixing bowl, beat the cream with a wire whisk or rotary beater until it forms stiff peaks.
Fold the cream into the fruit mixture.
Spoon the mixture into the prepared mould.
Place the mould in the refrigerator to chill for 2 hours or until the dessert has set and is firm.
To unmould the dessert, run a knife around the edge to loosen the sides.
Place a serving plate, inverted, over the mould and reverse the two, giving a sharp shake.
The cream should slide out easily.