Preheat the oven to 350F (180C).Butter eight 1/2 cup custard cups or ramekins, then dust with flour, tapping out the excess. Place on a sheet pan.
In a small heatproof bowl, combine the dates, baking soda, and boiling water. Let stand until cool, about 10 minutes.
In a bowl, whisk together the flour, baking powder and salt. In a large bowl, using an electric mixer, beat together the butter and brown sugar on medium speed until smooth and lighter in color, about 3 minutes. Add the eggs, one at a time, beating well after each addition and adding the vanilla and the final egg. Add the flour mixture and stir with a wooden spoon until well blended. Add the date mixture and stir until evenly distributed. The batter will be thin. Divide the batter evenly among the prepared custard cups, filling them about two-thirds full.
Bake the puddings until they are puffed and a toothpick inserted into the center comes out clean, about 20 minutes.
Make the Sauce
Meanwhile, make the sauce. In a saucepan over medium heat, melt the butter. Add the brown sugar and cream and whisk to incorporate. Bring to a boil for a minute or two, then add in the vanilla and salt.
Serving
When the puddings are ready, remove the oven and let cool for 5 minutes. Run a thin-blade knife around the inside of each custard cup to loosen the pudding and invert the warm pudding onto individual plates. Top each pudding with a big spoonful of the toffee sauce, letting it run down the sides and onto the plate. Top with vanilla ice cream to help cut the sweetness.
Notes
This recipe can be cooked up to a day ahead and reheated. The sauce can be made up to 3 days ahead, covered and stored in the fridge.