Preheat the oven to 350F. Combine the boiling water, chopped dates, and baking soda in a measuring jug, stir, and leave to sit for about 20 minutes until lukewarm.
Meanwhile, combine the butter, sugar and molasses in a food mixer using a paddle, then mix in the eggs, vanilla, salt, and flour until just combined. Stir in the cooled date mixture. Pour the batter into a greased baking dish - ours was 4"x6" and the pudding rose almost to the top; you could use a larger (8"x8") dish for less of a rise. Set oven timer for 30 minutes.
To make the sauce, click the link above.
The top of the pudding should be set but the center of the dish should still have a slight wobble to it. Using a toothpick or skewer, poke holes all over, down to the bottom of the pan, and pour in half of the toffee sauce. Let sit for 20 minutes, then broil if desired until the top is bubbly.
Serve with the rest of the warmed sauce and whipped cream.