Upside-Down Cake with Poached Dried Fruits

Preheat oven to 375F. Coat a 10-inch cast-iron (or similar ovenproof) skillet with cooking spray (see Equipment Note). Place eggs in a small bowl and cover with warm water to bring to room temperature while you prepare the topping.

To prepare topping: Cut larger pieces of dried fruit, such as peaches and pears, into halves or quarters so the cake will be easier to slice. Place fruit in a medium saucepan, cover with water and bring to a simmer. Reduce heat to low and simmer until soft, 10 to 15 minutes. Remove pieces as they become soft to prevent overcooking. When all the fruit is softened, remove from heat and drain.

Add 1 tablespoon butter to the prepared skillet and melt over low heat. Remove from heat and sprinkle with brown sugar. Using the back of a spoon, press the sugar evenly over the bottom of the skillet. Arrange the fruit attractively, cut side up, on the sugar.

To prepare cake: Whisk whole-wheat flour, all-purpose flour, baking powder, baking soda and salt in a large bowl. Mix buttermilk and vanilla in a measuring cup. Beat butter, oil and sugar in a mixing bowl with an electric mixer until smooth and creamy. Add eggs one at a time, beating between each addition until thoroughly smooth. Scrape down the sides of the bowl. With a rubber spatula, alternately fold in the dry ingredients and buttermilk, making 3 additions of dry and 2 additions of wet. Pour the batter over the fruit, spreading evenly.

Bake the cake until the top is golden and the cake starts to pull away from the sides, 25 to 30 minutes. Immediately loosen the edges with a knife. Place a serving plate over the skillet. Using oven mitts, grasp the plate and skillet together and carefully flip them over. Remove the skillet. Replace any fruits that adhere to the pan. Spoon any remaining syrup over the cake. Let cool for at least 20 minutes. Serve warm or at room temperature, using a sharp serrated knife to cut through the fruit layer first, then through the cake layer.