As soon as canned pineapple became readily available in the early 1900s, the pineapple evolved from a once-exotic symbol of hospitality into the latest food trend. But it really came into its own when it appeared on top of the pineapple upside-down cake. The recipe was based on the simple technique of cooking fruit in sugar and butter in a heavy skillet, topping it with cake batter, then baking it. To serve, the cake was turned “upside down.”
Sounds simple enough. But timing is key when unmolding an upside-down cake. When upended hot from the oven, the fruit layer is still too juicy and fluid, so it slides untidily over the cake layer. But if the cake cools for too long, the fruit will stick to the pan. The trick is cooling it for the perfect amount of time: 10 minutes. This is long enough to allow the fruit layer to firm up a bit so it adheres to the cake—but short enough so the cake will be easy to release from the pan—keeping the glistening, caramelized, deep amber topping right where it should be.
1. Make the caramel right in the cake pan: Melt 4 tablespoons butter in the cake pan in the oven, then stir in the brown sugar. This mixture will turn to a glossy caramel as the cake bakes.
2. Arrange the raw fruit in the pan: Lay the fruit evenly on top of the butter–brown sugar mixture. The fruit will cook and soften in the oven while the cake bakes.
3. Spread the cake batter over the fruit: Dollop the batter evenly over the raw fruit, then smooth the top gently so as not to disturb the layers of fruit and caramel.
4. Unmold the cake while warm: Let the cake cool in the pan for about 10 minutes, then lay a platter over the top of the cake pan and gently invert the cake onto the platter. Let the cake release itself from the pan, which will take about 1 minute. By letting the cake naturally release, you’ll ensure that it will release in one piece—if you try to force it, by tapping and shaking the pan, it might come out in chunks.