The caramel for this upside-down cake includes Demerara sugar, a coarse-textured raw sugar that has been partially refined. It comes from the Demerara area of Guyana.
9 Tbs. unsalted butter 1⁄2 cup Demerara sugar* 1 1⁄4 cups granulated sugar 1 Tbs. pure maple syrup 3 firm but ripe bananas, halved lengthwise 1⁄2 cup milk 1 tsp. vanilla extract 2 egg yolks 1 1⁄2 cups cake flour 1 1⁄2 tsp. baking powder 1⁄2 tsp. salt Lightly sweetened whipped cream for serving
Have all the ingredients at room temperature. Position a rack in the lower third of an oven and preheat to 350°F. Lightly butter the sides of a tarte Tatin pan.
In the tarte Tatin pan over medium heat, melt 3 Tbs. of the butter. Add the Demerara sugar, 1/4 cup of the granulated sugar and the maple syrup and stir to combine. Cook, stirring occasionally, until lightly caramelized, about 3 minutes. Remove the pan from the heat. Arrange the banana slices lengthwise, cut sides down, to cover the bottom of the pan in a single layer. Set aside.
In a small bowl, whisk together the milk, vanilla and egg yolks. Set aside.
In the bowl of an electric mixer fitted with the flat beater, sift together the flour, the remaining 1 cup granulated sugar, the baking powder and salt. Add the remaining 6 Tbs. (3/4 stick) butter and beat on medium-low speed until the butter forms pea-size pieces. Reduce the speed to low and slowly add the milk mixture, then stop the mixer and scrape down the sides of the bowl. Increase the speed to medium-high and beat until smooth, 1 to 2 minutes.
Spoon the batter over the bananas, spreading it evenly. Bake until a skewer inserted into the center comes out clean, about 50 minutes. Transfer the pan to a wire rack and let cool for 5 minutes. Run a small offset spatula or a knife around the edges of the pan to loosen the cake. Place a flat serving plate upside down on top of the pan and invert the pan and plate together. Let stand for 5 minutes, then lift off the pan. Slice and serve warm with whipped cream. Serves 8 to 10.
