01 - Preheat oven to 350°F. Grease and line an 8-inch square baking dish with parchment paper.
02 - Place chopped dates in a bowl, pour boiling water over them, stir in baking soda, and let sit for 10 minutes until softened.
03 - In a large bowl, beat softened butter and light brown sugar until light and fluffy using an electric mixer or whisk.
04 - Add eggs one at a time to the creamed mixture, beating well after each addition, then mix in vanilla extract.
05 - Sift together flour, baking powder, and salt. Gradually fold into the wet ingredients until combined.
06 - Lightly mash softened dates, then fold the dates and their soaking liquid into the batter until just combined.
07 - Pour batter into the prepared dish, smooth the surface, and bake for 35–40 minutes or until a skewer inserted comes out clean.
08 - Combine brown sugar, butter, heavy cream, golden syrup, vanilla, and salt in a saucepan. Heat gently, stirring until butter and sugar melt. Increase heat to simmer for 3–4 minutes until thickened.
09 - Pierce the warm pudding all over with a skewer. Pour half the warm toffee sauce on top and let soak for 10 minutes.
10 - Cut pudding into portions and serve warm, drizzled with remaining toffee sauce. Optionally accompany with vanilla ice cream or custard.