Preheat the oven to 375°F and set an oven rack to the middle position. Prepare an 8 x 8 cake pan with butter and flour, making sure the cake pan will fit inside a larger pan for a bain-marie when it is time for the cake to go into the oven.
Combine the roughly chopped dates, the orange juice (or orange juice and water) and the finely grated ginger in a medium size pan; make sure the pan is a bit bigger than you need as the mixture will foam up at the end of the cooking process. Cook over medium heat for 15-20 minutes until the dates are very soft and starting to break down. Add in the baking soda and stir. The mixture will foam up quite a bit and then subside. Set aside to cool for about 20 or 30 minutes.
While the date mixture is cooling, make the cake batter. In a medium bowl, sift together the flour, the baking powder, and the salt. Set aside. If using an eclectic mixer, put the butter and granulated cane sugar into a large bowl, and beat until light and fluffy, or use the bowl and paddle attachment of a stand mixer to do the same. Add in the eggs, 1 at a time, and then beat again, until incorporated, until each egg is added and fully mixed in. Add the flour in by the large spoonful, beating briefly after each addition, until all the flour is just incorporated. It’s ok if a few tiny floury patches remain. At this point you will have a thick cake batter.
Put the kettle on, so that you will have a large quantity of just boiled water to set up the bain marie.
Add the cooled date mixture to the cake batter, mixing to combine, but not over-mixing - it’s ok if there are a few areas of plain cake batter marbled amongst the date and cake mixture. Spoon the batter into the prepared cake pan and place the cake pan into the larger pan.
Open the oven door and pull out the middle rack, and place the larger cake pan on the rack. Now pour the just boiled water into the larger pan, making sure not to splash water into your cake pan, until the water comes about halfway up the smaller cake pan. Gently push the oven rack in and close the oven door.
Bake for about 40 minutes; make the Salted Vanilla Toffee Sauce while the cake is baking (see below).
At the 40 minute mark, test the cake with a wooden skewer. If there is still cake batter on the skewer, continue to bake for additional 5 minute increments until the skewer comes out clean; as actual oven temperatures vary the actual baking time is variable. The cake will be very moist, and you may see goey dates on the skewer, but you should not see actual uncooked batter.
Carefully remove the cake pan from the bain-marie and set down on a rack to cool down a bit. (Turn off the oven and let the pan containing the water cool until it is safe enough to remove the pan and dispose of the water.) Use a wooden skewer to poke holes into the cake, and pour a bit of the Salted Vanilla Toffee Sauce over top, using a spatula if needed to completely lacquer the top of the cake with sticky, shiny sauce.
Serve the cake warm; cut into squares, and pour a generous portion of the warm Salted Vanilla Toffee Sauce over or puddled under each serving, and top with optional vanilla ice cream, or my favourite, unsweetened vanilla bean flecked whipped cream.