1 stick (1/2 cup) unsalted butter
3/4 cup packed light brown sugar
10 or 11 small (2- to 2 1/4-inch) fresh apricots (about 1 1/4 lb), halved lengthwise and pitted
1 3/4 cups all-purpose flour
1 1/2 teaspoons baking powder
1/2 teaspoon baking soda
1/2 teaspoon salt
1 stick (1/2 cup) unsalted butter, softened
3/4 cup granulated sugar
1 1/2 teaspoons vanilla extract
1/4 teaspoon almond extract
2 large eggs at room temperature
3/4 cup well-shaken buttermilk
Preheat oven to 375°F.
Heat butter in a 10-inch well-seasoned cast-iron or heavy nonstick skillet (at least 2 inches deep) over moderate heat until foam subsides. Reduce heat to low and sprinkle brown sugar evenly over butter, then cook, undisturbed, 3 minutes (not all of sugar will be melted). Remove skillet from heat and arrange apricot halves, cut sides down, close together on top of brown sugar.
Sift together flour, baking powder and soda, and salt into a small bowl.
Beat together butter, sugar, and extracts in a large bowl with a mixer at medium speed until pale and fluffy, 2 to 3 minutes. Beat in eggs 1 at a time, then beat until mixture is creamy and doubled in volume, 2 to 3 minutes.
Reduce speed to low and add flour mixture in 3 batches alternately with buttermilk, beginning and ending with flour mixture, and beat just until combined.
Gently spoon batter over apricots and spread evenly.
Bake cake in middle of oven until golden brown and a wooden pick inserted in center comes out clean, 40 to 45 minutes.
oven mitts, immediately invert a large plate over skillet and, keeping
plate and skillet firmly pressed together, invert cake onto plate.Take
care doing this, the skillet will be very hot! Carefully lift skillet
off cake and, if necessary, replace any fruit that is stuck to bottom
of skillet. Cool to warm or room temperature.