Pineapple and upside-down cake are so firmly paired in my culinary consciousness that it seemed a bit odd to make an upside-down cake with plums, until I tasted the result.
The sweet taste of fresh black plums is wonderfully enhanced by the delicate caramel glaze of brown sugar and butter, and the deep black and reddish plums stand out in gorgeous contrast to the pale lemony cake.
After the plums are halved and pitted, assembling the cake takes about 15 minutes from processor to oven. The batter is a snap to make because the ingredients are simply added to the machine and processed in.
The most critical step in the cake-making process is incorporating the sifted dry ingredients into the batter already in the machine. I have found it especially easy to stir dry ingredients together thoroughly in a bowl, then transfer them to a medium-size strainer set over the processor container.
I sift ingredients directly into the processor and over the batter in two batches by gently tapping the side of the strainer (a medium-size sifter is also convenient). Then I replace the lid and very carefully incorporate the sifted dry ingredients into the batter with half-second pulses--a few short on/off bursts of the machine.
The number of these quick pulses will vary with the size of the processor container but often it takes just four or five--a total of 2 to 2 1/2 seconds. The quick-pulsing technique to mix dry ingredients into a batter can be used with any type of processor-made cake, and half-second pulses always are used.
The important thing to remember is to let the machine run as little as possible and, once the dry ingredients disappear, to stop processing immediately.
LEMON-BLACK PLUM UPSIDE-DOWN CAKE
6 to 8 large black plums
1 medium lemon
1/2 cup granulated sugar
10 tablespoons unsalted butter, softened
1 1/4 teaspoons vanilla
1 1/2 cups flour
2 teaspoons baking powder
2/3 cup milk
1/2 cup light brown sugar, packed
Whipped cream or sour cream
Rinse plums, then pat dry, cut in halves and remove pits. Set plum halves aside.
Insert metal blade in dry processor. Strip off lemon peel with vegetable peeler, allowing strips to fall into processor. Add granulated sugar and process until peel is minced, about 1 minute. Add 6 tablespoons butter and process until mixed, then add eggs and vanilla. Process 20 seconds.
Sift together flour and baking powder. Mix half of flour mixture and half of milk into batter with half-second pulses. Repeat with remaining flour and milk.
Melt remaining 4 tablespoons butter in 9-inch cast-iron skillet or other heavy oven-proof skillet. Add brown sugar and stir over medium heat until sugar melts. Remove from heat, then add plums, cut-sides up, working carefully since sugar mixture is very hot.
Using finger to hold processor blade in place underneath container, pour batter evenly over plums. Use rubber spatula to spread and gently press batter evenly over plums. Place skillet on baking sheet to catch any spillover of plum juices as cake cooks.
Bake on lowest oven rack at 375 degrees 30 to 35 minutes or until wood pick inserted into center of cake is withdrawn clean. Transfer skillet to cake rack and cool 10 minutes. Unmold cake over a platter by carefully inverting skillet. Serve with whipped cream or sour cream. Makes 6 to 8 servings.