Nutrition per serving may change if servings are adjusted.
1 tablespoon butter, melted
3 tablespoons light brown sugar
3 firm ripe pears, such as Bartlett or Bosc
1 tablespoon lemon juice
1 1/4 cups sifted cake flour
1/2 teaspoon baking powder
1/2 teaspoon baking soda
1/2 teaspoon salt
2 teaspoons ground cinnamon
1 teaspoon ground ginger
1/2 teaspoon ground allspice
1/4 teaspoon ground nutmeg
1/2 cup granulated sugar
2 large egg whites
1/2 cup buttermilk
1/4 cup molasses
2 tablespoons canola oil
Position rack in the lower part of the oven; preheat to 375 °F. Coat an 8-inch square baking pan with cooking spray.
Pour butter into the prepared pan and tilt to coat the bottom evenly. Sprinkle brown sugar over the butter. Peel, halve and core pears. Brush with lemon juice. Cut a pear half crosswise into 1/8-inch-thick slices. Keeping the slices together, slide a metal spatula underneath and invert the sliced pear half onto your hand, pressing to fan slightly. Place it, rounded side down, over the brown sugar in the baking dish. Repeat with the remaining pear halves. Bake, uncovered, for 15 minutes.
Meanwhile, sift together flour, baking powder, baking soda, salt, cinnamon, ginger, allspice and nutmeg into a bowl. Stir in granulated sugar. Whisk together egg whites, buttermilk, molasses and oil in a large bowl. Add the dry ingredients to the egg white mixture and stir with a wooden spoon or rubber spatula just until blended.
When the pears have baked for 15 minutes, pour the batter evenly over top. Bake until a cake tester inserted in the center comes out clean, 30 to 35 minutes.
Loosen edges of the cake. Invert a serving platter on top of the baking pan and, grasping firmly with hands protected with oven mitts, quickly turn the cake and platter over. Remove the baking dish. Remove any pear slices that adhere to the pan and replace them on top of the cake. Let cool for at least 10 minutes, cut into squares and serve warm.