Preheat oven to 350 °F (175 °C). Grease an 8‑inch square baking pan.

In a bowl, combine chopped dates with baking soda and pour over boiling water. Let sit 10 minutes until dates soften.

In a separate bowl, cream butter and brown sugar until light and fluffy. Beat in eggs one at a time, then stir in vanilla.

Sift flour, baking powder, and salt into the butter mixture; stir until just combined. Gently fold in the date mixture.

Pour batter into prepared pan and bake for 25–30 minutes, or until a toothpick inserted in the center comes out clean.

Meanwhile, make the toffee sauce: melt butter and brown sugar in a saucepan over medium heat, stirring until sugar dissolves. Remove from heat and whisk in cream and vanilla until smooth.

Remove pudding from oven, poke holes over top with a skewer or fork, and pour half the toffee sauce over it to soak in.

Serve warm with remaining sauce spooned over each portion.