1) In a pan, combine the raspberries and currant jelly together, bring to a boil.
2) In a bowl, stir the cornstarch in water, until well blended.
3) Stir into the raspberry mixture and simmer over a low heat, stirring occasionally, until thickened.
4) Stir in the almond extract, strain and allow to cool.
5) Spoon the chilled melon balls into sherbet glasses, top with raspberry sauce and serve the Melons Melba immediately.