CAKE INGREDIENTS: • 6 tablespoons unsalted butter, room temperature, plus more for dish
• 1 1/2 cups all-purpose flour, plus more for dish
• 8 ounces Medjool dates, pitted and coarsely chopped (about 1 1/4 cups)
• 1 cup scalding-hot strong brewed coffee
• 1 tsp baking soda
• 1 tsp baking powder
• 1/2 tsp coarse salt
• 3/4 cup lightly packed dark-brown sugar
• 2 large eggs, room temperature
SAUCE INGREDIENTS: • 1 stick unsalted butter
• 1 cup lightly packed dark-brown sugar
• 3/4 cup heavy cream
CAKE DIRECTIONS: Preheat oven to 325 degrees. Butter and flour a 2 1/2-quart baking dish. Place dates in a bowl, pour coffee over dates, and let soak 15 minutes. Stir in baking soda.
Whisk together flour, baking powder, and salt. Beat together butter and sugar with a mixer on medium-high speed until pale and fluffy, about 3 minutes. Reduce speed to medium and beat in eggs, 1 at a time, until thoroughly incorporated.
Reduce speed to low and add half the flour mixture, beating until combined. Add date mixture and remaining flour mixture, and beat until just combined. (Do not overmix.) Transfer batter to dish, and bake until cake is puffed and springs back in center when gently pressed with a finger, about 25 minutes.
SAUCE DIRECTIONS: Meanwhile, combine butter, sugar, and cream in a medium saucepan and bring to a boil over high heat. Reduce heat to medium (so sauce does not boil over) and boil, stirring frequently, until sauce thickens and darkens slightly, about 4 minutes.
Remove cake from oven and pierce holes at 1-inch intervals to bottom of cake with a wooden skewer. Pour half of hot sauce over cake and let soak 20 minutes. Serve warm with remaining sauce.
Cake soaked in sauce and remaining toffee sauce can be stored at room temperature up to 1 day. Before serving, warm cake in a 300 degrees oven 10 minutes, and sauce in a small saucepan over medium heat.