LATE SUMMER SWEETNESS: PLUM CASHEW UPSIDE DOWN CAKE

The marriage of plums, brown sugar, butter and toasty cashews is a holy one. Plums are one of the key symbols of summer for me, and at this stage, I'm up to about 4 per day. My addiction runs strong for these jewel-like orbs and this upside down cake Roxanne Rosensteel made for this story is a new classic you've got to make before these plum days run their course. I'm whipping one up this week to serve with a mountain of vanilla ice cream.

This cake pairs well with the Matilija Musk cocktail from yesterday -- lavender tea, neat whisky or a cold glass of milk also hit the spot. The pattern the folding slices of caramelized plum are glorious, needing no adornment; I love cakes that decorate themselves!

Plum Cashew Upside Down Cake 
makes one 9" cake 

for the topping: 
4 tablespoons unsalted butter
3/4 cup brown sugar
5 ripe plums cut into 1/2" slices

for the cake: 
1/2 cup unsalted butter, room temperature
1 cup sugar
1 teaspoon vanilla extract
1 lemon, zested
2 eggs separated, room temperature
3/4 cup all purpose flour
3/4 cup cake flour
3/4 cup cashews, toasted
2 teaspoons baking powder
1/4 teaspoon salt
1/2 cup whole milk
1/4 cup cream of tartar

Preheat oven to 350 degrees. Put 1/4 cup of butter into a 9” cast iron skillet and melt over medium heat. Add the brown sugar and stir to dissolve. Place the plum slices on top of the melted sugar so that they are overlapping, fanned out into circles.

For the cake, grind the cashews with 3 tablespoons of the all purpose flour in a spice grinder or food processor. In a medium sized bowl, whisk together the remaining all purpose flour, cake flour, ground cashews, baking powder and salt. In the bowl of a stand mixer, cream together the 1/2 cup of butter and sugar for 5 minutes on medium speed. Beat in the vanilla extract and lemon zest. Beat in the egg yolks one at a time. In five alternating parts, mix in the dry and the whole milk on slow speed, starting and ending with the dry. Scrape the sides of the bowl between each addition. In a separate bowl, whisk the egg whites and cream of tartar til it holds medium-stiff peaks. Fold the egg whites into the cashew batter in three parts, so the cake is lightened, but cohesive.

Gently spread the cake batter over the plums in the cast iron skillet. Bake for 40 minutes, til the cake just springs back when touched. Once skillet is cool enough to handle, but still warm, cover the skillet with a large plate or platter, and swiftly flip the cake upside down and onto the platter to release the cake.