Preheat the oven to 350 degrees F and butter an 8½-inch porcelain soufflé dish (or similar-sized baking dish).
Make the toffee sauce by bringing the cream, dark brown sugar, golden syrup (or molasses) and salt to a boil in a medium saucepan, stirring often to melt the sugar.
Lower heat and simmer, stirring constantly for about 5 minutes, until the mixture is thick and coats the spoon. Pour half the sauce into the prepared soufflé dish and place the dish in the freezer, and reserve the other half for serving.
To make the pudding, in a medium saucepan, heat the dates and water. Once the water begins to boil, remove from heat and stir in the baking soda. Set aside, but keep it slightly warm.
In a small bowl, whisk together the flour, baking powder, and salt.
In the bowl of a standing electric mixer, or by hand, beat the butter and granulated sugar until light and fluffy. Gradually beat in the eggs, then the vanilla. (Don’t be alarmed if the mixture looks a bit curdled.)
Stir in half of the flour mixture, then the date mixture, then add the remaining flour mixture until just mixed. Don’t overbeat the batter.
Remove the soufflé dish from the freezer and scrape the batter into the soufflé dish and bake for 50 minutes, or until a toothpick inserted into the center comes out with moist crumbs attached.
Remove the pudding from the oven, and let cool slightly before serving. Spoon portions of the cake into serving bowls and douse with additional warm toffee sauce. Whipped cream or vanilla ice cream are good accompaniments, although I enjoy it just as it is.