Preheat oven to 180°C Mix dates and baking soda in a heat proof bowl. Pour boiling water on top and leave to stand.
Cream butter and sugar until pale, then add eggs, one at a time, beating well after each addition.
Gently fold in the sifted flour, stir in the date mixture and pour into a greased 18cm cake tin. Bake for 30-40 minutes.
Sauce: ¾ cup brown sugar, 1 cup cream, 1/2 teaspoon vanilla essence, 1 tablespoon butter. Combine sugar, cream, vanilla and butter in a saucepan, bring to the boil, stirring and simmer for 5 minutes. Cut pudding into wedges and pour hot sauce over.