Sauteed apples are the fruit of choice for this upside-down cake. The cinnamon and ginger cake tastes best while still slightly warm and with lots of whipped cream.
Place oven rack in lower third of oven. Heat oven to 350°F.
Generously butter bottom of 10-inch-round cake pan with 2 tablespoons butter. Sprinkle with light brown sugar.
Heat remaining 2 tablespoons butter in large skillet over medium heat. Add apples; saute until tender, 12 to 15 minutes. Let cool slightly.
Sift flour, baking powder, ginger, cinnamon and salt into bowl.
Beat together butter and dark-brown sugar in clean large bowl on medium-high speed until smooth, 3 to 5 minutes. Add eggs, one at a time, beating well after each addition; then beat until smooth, about 1 minute. Beat in vanilla.
On low speed and in 2 batches, beat flour mixture alternately with milk into butter mixture; scrape down sides of bowl after each flour addition. Then beat until mixture is smooth, 1 to 2 minutes.
Arrange apples over bottom of prepared cake pan. Spoon batter over apples, spreading evenly.
Bake in lower third of 350°F oven until toothpick inserted in center of cake comes out clean, 45 minutes. Let pan cool on rack 5 minutes.
To unmold, run small knife around edge of pan to loosen cake. Invert serving plate over top of pan; quickly turn plate and pan over together; carefully remove pan. Replace any apples that have stuck to bottom of pan. While still warm, garnish by brushing generously with melted jelly. Serve slightly warm or at room temperature with whipped cream.