01 - Preheat oven to 350°F. Grease an 8x12 inch baking dish or 8 ramekins.
02 - Place chopped dates in a bowl, pour boiling water over them, stir in baking soda, and let sit for 10 minutes.
03 - In a large bowl, beat softened butter and brown sugar together until light and fluffy. Add eggs one at a time, then mix in vanilla extract.
04 - Mash the soaked dates with their liquid to a rough paste and fold into the butter mixture.
05 - Sift in self-raising flour and salt, then gently fold until just combined, avoiding overmixing.
06 - Pour batter into the prepared dish or divide among ramekins. Bake for 30–35 minutes until risen and a skewer comes out clean.
07 - Melt butter and brown sugar in a saucepan over medium heat. Stir in cream, vanilla, and salt. Simmer for 3–4 minutes until slightly thickened.
08 - Prick the warm sponge with a skewer, pour half of the toffee sauce over it, and let it soak for 10 minutes.
09 - Drizzle with the remaining toffee sauce and serve warm with vanilla ice cream or whipped cream if desired.