1/2 medium pineapple, peeled, quartered lengthwise, and cored
3/4 stick unsalted butter
3/4 cup packed light brown sugar
1 1/2 cups all-purpose flour
2 teaspoons baking powder
1/4 teaspoon salt
3/4 stick unsalted butter, softened
1 cup granulated sugar
2 large eggs
1 teaspoon vanilla
1 tablespoon dark rum
1/2 cup unsweetened pineapple juice
2 tablespoons dark rum for sprinkling over cake
Preheat oven to 350°F.
Make topping: Cut pineapple crosswise into 3/8-inch-thick pieces. Melt butter in a small saucepan. Add brown sugar and simmer over moderate heat, stirring, four minutes. Remove from heat and pour into a 9" cake pan. Arrange pineapple on top of sugar mixture in concentric circles, overlapping pieces slightly.
Make batter: Sift together flour, baking powder, and salt. Beat butter in a large bowl with an electric mixer until light and fluffy, then gradually beat in granulated sugar. Add eggs, one at a time, beating well after each addition. Beat in vanilla and rum. Add half of flour mixture and beat on low speed just until blended. Beat in pineapple juice, then add remaining flour mixture, beating just until blended. (Batter may appear slightly curdled.)
Spoon batter over pineapple topping and spread evenly. Bake cake in middle of oven until golden and a tester comes out clean, about 45 minutes. Let cake stand for five minutes. Run a knife around the edges to loosen the cake. Invert a plate over cake pan and invert cake onto plate (keeping plate and pan firmly pressed together). Replace any pineapple stuck to bottom of pan. Sprinkle rum over cake and cool on plate on a rack.
Serve cake just warm or at room temperature. And add some vanilla ice cream, you won't regret it.
Do ahead: Cake may be made one day ahead and chilled, covered. Bring to room temperature before serving.
Caramel making and nesting
Some rum for sprinkling on the final cake
Pretty as a picture