apple pear upside-down cake with vanilla infused butter

Between the title and the pictures, I’m not sure there’s much else to say. The recipe is a bit intricate, but pretty easy. The flavor is complex, with butterscotch and vanilla undertones. The topping is almost crisp, and the cake has a wholesome, moist crumb. I highly recommend it.

A quick note on the recipe–you really do need to measure carefully when baking cakes or cookies. You probably knew this, but I thought I was above the rules of science.

Apple and Pear Upside-Down Cake with Vanilla Infused Butter (adapted from Cook’s Illustrated)

for the fruit
4 tablespoons unsalted butter
2″ section of fresh vanilla bean (optional)
2 fresh apples
2 ripe pears
2/3 cup packed light brown sugar
2 tablespoons fresh lemon juice

for the cake
1 cup unbleached all-purpose flour
1 teaspoon baking powder
1/2 teaspoon (or heaping if you have a salt tooth) kosher salt
2 large eggs
3/4 cup sugar
1/4 packed light brown sugar
2 eggs
6 tablespoons room temperature butter
1/2 cup sour cream
1 teaspoon vanilla extract

In a large stainless steel or enamel skillet (not cast iron), gently heat the 4 tablespoons butter, until it is bubbly and fragrant. Add the vanilla bean and set aside for 10 minutes or more while you prepare the fruit.

Preheat the oven to 350 degrees. Core and cut the pears into 1/2 inch slices. Then core, and cut the apples into 1/4 inch slices. Remove the vanilla bean from the pan and gently rewarm the butter. Add the pears and cook over medium heat for 5 or so minutes, until they just start to brown. Add the apples, brown sugar, and lemon, and stir gently while the sugar dissolves, cooking for a minute or two. Remove from heat and set aside while you make the cake batter.

In a smallish bowl, combine the flour, baking powder, and salt. In a medium bowl, fluff the room temperature butter with your beater, or a paddle if using a stand mixer. Then add the sugars and beat until fluffy. Stir in the eggs just until combined, and then add the sour cream and vanilla. Gradually stir in the flour.

Tilt the pan with the fruit so that the butter coats the sides, then pour in the cake batter. Gently set into the oven, and cook until cake is golden and toothpick inserted in the middle comes out clean, 35-40 minutes. Cool pan on a rack for 20 minutes, then carefully invert onto wire rack and cool another 20 minutes or so before removing to a large serving plate. Serve in slices all by itself, or with barely sweetened lightly whipped cream. Wrap up over night–it makes for an excellent breakfast too.

12.30.09 Update: I made this cake again over the holiday and had remarkably different results. In the first place, I had relatively unripe pears this time and I cooked them for much longer so that they were rather overcooked by the time I added the batter. The end result was a much moister cake, bordering on a pudding. It was sill really good, though. If you want a fluffier cake and fruit with bite, use just ripe fruit, and saute for the short five minutes over medium to medium high heat (just so the butter doesn’t smoke). If you want a more dense pudding-like cake, cook the fruit longer until the edges are quite soft. In both cases, remove from oven when a toothpick inserted in the middle comes out clean. It will take longer for the second cake to cook, look for it to set in the middle.