Place the chopped dates in a bowl and stir in the baking soda. Pour the boiling water over the dates and let them sit for about 10 minutes. This softens the dates and brings out their sweetness.
In a separate bowl, cream together the softened butter and granulated sugar until light and fluffy. This usually takes about 3-5 minutes with an electric mixer.
Beat in the eggs one at a time, making sure each egg is fully incorporated before adding the next.
In another bowl, whisk together the flour, baking powder, and salt. This ensures that the baking powder is evenly distributed.
Gradually add the dry ingredients to the creamed mixture, alternating with the date mixture. Start and end with the dry ingredients. Mix until just combined, being careful not to overmix.
Grease and flour a 12-cup muffin tin. Fill each muffin cup about two-thirds full with the batter.
Bake in a preheated oven at 350°F (175°C) for 20-25 minutes, or until a toothpick inserted into the center comes out clean.
While the puddings are baking, prepare the toffee sauce. In a saucepan, combine the heavy cream, brown sugar, and butter.
Cook over medium heat, stirring constantly, until the butter is melted and the sugar is dissolved. Bring to a simmer and cook for about 5 minutes, or until the sauce has thickened slightly.
Remove the sauce from the heat and stir in the vanilla extract.
Once the puddings are out of the oven, let them cool slightly in the muffin tin for a few minutes. Then, gently remove them from the tin and place them on a serving plate.
Poke holes in the top of each pudding with a fork and pour the warm toffee sauce over the puddings. Make sure each pudding is generously covered.