Preheat the oven to 180°C (350°F) for a conventional oven (or 160°C / 320°F for convection ovens). Grease an 8-inch cake pan and line the base with parchment paper. Set aside.

In a large bowl, combine the pitted dates, baking soda, and boiling water. Stir and let the mixture sit for about 10 minutes to soften.

Sift together the flour, baking powder, and salt into a separate bowl. Set aside.

Once the dates have soaked, mash them gently with a fork, leaving some small chunks for texture.

Add the brown sugar, melted butter, egg, and vanilla extract to the mashed dates. Whisk until the mixture is well combined and smooth.

Gradually add the sifted dry ingredients to the wet mixture. Gently fold them in with a spatula until the batter is just combined. It’s okay if it’s a little lumpy, as long as there are no large pockets of dry flour.

Pour the batter into the prepared cake pan. Tap the pan gently on the counter to remove any large air bubbles. Bake for about 33 minutes or until a toothpick inserted into the center comes out clean or with a few moist crumbs.

Allow the cake to cool in the pan for 20 minutes, then transfer it to a wire rack to cool completely. Let it cool right side up to avoid the dome from breaking.

In a small saucepan, combine the butter, brown sugar, heavy cream, and vanilla extract. Stir over medium heat until the mixture comes to a boil.

Allow the sauce to boil for about 5 minutes, stirring frequently, until it thickens slightly.

Remove the sauce from heat and transfer it to a heatproof bowl to cool. It will continue to thicken as it cools. Drizzle the warm butterscotch sauce over slices of the cooled date cake.