Preheat oven to 350°F (175°C).
Mix chopped dates and baking soda in a bowl.
Pour boiling water over dates. Let sit.
Cream butter and brown sugar in a bowl.
Add eggs, one at a time, beating well.
Mix in flour, baking powder, and salt.
Stir in date mixture until combined.
Pour batter into greased baking dish.
Bake for 30-35 minutes, until firm.
Meanwhile, make toffee sauce: melt butter in a saucepan.
Stir in brown sugar, cream, and corn syrup.
Cook, stirring, until smooth and thickened.
Pour sauce over baked pudding before serving.