01 - Preheat oven to 350°F. Grease and line an 8-inch square cake pan with parchment paper.
02 - Place the chopped dates in a bowl, pour boiling water over, then stir in baking soda. Let the mixture sit for 10 minutes to soften.
03 - In a large bowl, cream softened butter with dark brown sugar until light and fluffy. Add eggs one at a time, beating well after each addition, then mix in vanilla extract.
04 - Gently fold the self-raising flour and salt into the creamed mixture until just combined.
05 - Lightly mash the soaked dates with their soaking liquid and fold into the batter carefully.
06 - Transfer batter into the prepared pan and bake for 30 to 35 minutes, or until a skewer inserted into the center comes out clean.
07 - While the pudding bakes, combine dark brown sugar, butter, and heavy cream in a saucepan over medium heat. Stir until sugar dissolves and mixture simmers. Cook for 4 to 5 minutes stirring occasionally until thickened. Remove from heat and stir in vanilla extract and salt.
08 - Allow the baked pudding to cool for 5 minutes. Use a skewer to poke holes over the surface and pour half of the warm toffee sauce over it. Let absorb for 10 minutes.
09 - Cut into squares and serve warm, drizzling remaining toffee sauce over each portion.