Preheat oven to 350°F (175°C) and lightly grease a baking dish.
Soften dates by pouring boiling water over them. Add baking soda, stir, and let sit 10 minutes.
Blend the dates into a smooth paste.
Cream butter and sugar together in a bowl until fluffy.
Add eggs one at a time, then mix in vanilla.
Stir in flour, baking powder, and salt.
Fold in the date mixture until smooth.
Pour batter into the prepared dish and bake for 25–30 minutes, until golden and springy.
Make the toffee sauce: melt butter, sugar, and cream together over low heat until smooth.
Serve warm, drizzling the lighter toffee sauce over the pudding.