Prepare the dates: Place the chopped dates in a medium heatproof bowl. Pour the 1 cup of boiling water over the dates and sprinkle the 1 teaspoon baking soda on top. Stir gently and let the mixture sit for about 10 minutes. The dates will soften and the mixture will thicken slightly; this helps create that moist, almost pudding-like texture.
Chopped dates soaking in hot water
Chopped dates soaking in hot water
Mix the wet ingredients: In a large bowl, whisk together the melted 1/2 cup butter and the granulated sugar until the mixture looks glossy and slightly thickened. Add the eggs one at a time, whisking well after each addition, then whisk in the vanilla extract. You want everything fully combined but not over-beaten.
Combine the dry ingredients: In a separate small bowl, whisk together the flour, baking powder, and 1/4 teaspoon salt. This ensures the leavening is evenly distributed so the cake rises uniformly.
Build the batter: Stir the softened date mixture (including all the liquid) into the butter-sugar-egg mixture until evenly combined. The mixture may look a bit loose and speckled with dates—that’s exactly right. Gently fold in the flour mixture with a spatula just until no dry streaks remain. Overmixing can toughen the crumb, so stop as soon as it comes together.
Sticky date batter being folded in a mixing bowl
Sticky date batter being folded in a mixing bowl
Bake the pudding base: Pour the batter into the prepared glass baking dish and smooth the top. Bake on the center rack for 25–30 minutes, or until the top is set, shiny, and a toothpick inserted near the center comes out with a few moist crumbs but no wet batter. While it bakes, the dates will sink a bit and the edges will start to caramelize against the glass.
Make the sticky topping sauce: During the last 5–10 minutes of baking, combine the 1/2 cup brown sugar, 1/4 cup butter, 1/4 cup water or milk, and a pinch of salt in a small saucepan. Cook over medium heat, stirring frequently, until the butter melts and the mixture comes to a gentle simmer. Let it bubble for 1–2 minutes, stirring, until it looks smooth and glossy. Remove from heat; it will thicken slightly as it stands.
Brown sugar sauce simmering in a small saucepan
Brown sugar sauce simmering in a small saucepan
Finish the pudding: As soon as the cake comes out of the oven, poke it all over with a skewer or fork, going about halfway down into the cake. Slowly pour the warm brown sugar sauce evenly over the hot cake, letting it soak in and pool along the edges. The top will turn a deeper glossy caramel-brown as the sauce seeps into the crumb.
