Each fall, Sunset’s food editor Margo True looks forward to making her recipe for this spicy, tender cake with plump Medjool dates from the West. “They make it totally irresistible,” she says. (Several Test Kitchen tasters are still licking their fingers.)
Make toffee sauce: Melt butter in a medium saucepan. Whisk in whipping cream, brown sugar, and molasses. Cook at a low boil, whisking occasionally, until dark reddish-brown, 7 to 8 minutes. Stir in vanilla and salt and set aside.
Preheat oven to 325° with a rack in the center.
Make pudding: Bring 11/4 cups water to a boil in a small saucepan. Remove from heat and stir in 1 tsp. baking soda; then stir in dates. Let cool.
In a medium bowl, whisk 11/2 cups flour with remaining 2 tsp. baking soda and the salt; set aside. Butter bottom of an 8-in. square baking pan and line with a piece of parchment paper cut to fit, smoothing out wrinkles. Butter and flour pan, including parchment. Cover bottom evenly with walnuts, rounded sides down; then pour 3/4 cup Dark Toffee Sauce evenly over nuts to barely coat.
Meanwhile, in a stand mixer with the paddle attachment, cream 5 tbsp. butter and the sugar on medium speed until light and fluffy, about 4 minutes. Dissolve espresso in vanilla, then beat into bowl along with eggs. Reduce speed to low and, in 2 batches, beat in flour mixture. Stir in date mixture (with liquid). Pour batter into pan.
Bake cake until a skewer inserted in center emerges with a few crumbs sticking, about 45 minutes. (It will look very dark when done.) Let cool 15 minutes in pan on a wire rack, then invert onto a rimmed platter. Peel off parchment and let cool at least 15 minutes more.
Cut cake into squares and serve with remaining Dark Toffee Sauce, for drizzling.
Serving Size 1 slice, 2 tbsp. of sauce
* Percent Daily Values are based on a 2,000 calorie diet. Your daily value may be higher or lower depending on your calorie needs.