- 2 cups all-purpose flour
- 2 teaspoons baking powder
- 1 teaspoon baking soda
- ½ teaspoon ground cinnamon
- ½ teaspoon salt
- 1 cup (2 sticks) unsalted butter, at room temperature
- 2/3 cup packed light brown sugar
- 2/3 cup granulated sugar
- 4 large eggs, at room temperature
- One 15-ounce can solid-pack pumpkin (1¾ cups)
- 1 cup packed light brown sugar
- 8 tablespoons (1 stick) unsalted butter
- 1/3 cup light corn syrup
- 1½ cups heavy cream
- Sweetened whipped cream, for serving
- To make the cake, position a rack in the center of the oven and preheat the oven to 350°F. Lightly butter a 13 × 9-inch baking pan.
- Sift together the flour, baking powder, baking soda, cinnamon, and salt. Beat the butter, brown sugar, and granulated sugar in a large bowl with an electric mixer on high speed until the mixture is light and fluffy, about 3 minutes. One at a time, beat in the eggs. Beat in the pumpkin. If the mixture curdles, do not worry. With the mixer on low speed, beat in the flour mixture in 3 additions, beating until smooth after each addition and scraping down the sides of the bowl as needed. Spread in the baking pan.
- Bake until a toothpick inserted in the center of the cake comes out clean, 30 to 35 minutes.
- Meanwhile, make the sticky toffee sauce. Melt the brown sugar, butter, and corn syrup in a heavy-bottomed large saucepan over medium heat, stirring often to help dissolve the sugar. Whisk in the cream and bring to a boil, taking care that the mixture does not boil over. Cook uncovered, whisking often, until the sauce is glossy, smooth, and thick enough to nicely coat a wooden spoon, about 8 minutes. Turn off the burner so the sauce is kept warm by the burner’s residual heat.
- When the cake is done, transfer it to a wire cake rack. Using a meat fork, pierce the cake all over. Pour and spread about 1 cup of the toffee sauce over the cake. Let stand for 10 minutes.
- Spoon the warm cake into individual bowls, top with more of the warm sauce, and garnish with a dollop of whipped cream. Serve immediately.