Preheat your oven to 350°F (175°C). Grease a 9-inch round cake pan and line the bottom with parchment paper.

In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside.

In a large mixing bowl, cream the softened butter and brown sugar together until light and fluffy. Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.

In a separate bowl, combine the chopped dates and boiling water. Let it sit for about 10 minutes until the dates soften.

Add the date mixture (including the water) to the butter mixture and mix until combined. Gradually fold in the dry ingredients until just combined.

Pour the batter into the prepared cake pan and bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean.

While the pudding is baking, prepare the toffee sauce. In a saucepan over medium heat, combine the heavy cream, dark brown sugar, butter, and vanilla extract. Stir until the sugar dissolves and the mixture is smooth. Bring to a gentle simmer and cook for 5 minutes, then remove from heat.

Once the pudding is done, let it cool in the pan for 10 minutes before inverting it onto a serving plate.

Serve warm, drizzled with the toffee sauce.