Upside-Down Apple Cake with Walnut and Sage

For Apple, Walnut, Sage & Caramel

• 1 crisp, sweet, slightly tart apple, such as a Braeburn
• 5 tablespoons walnuts
• 5 sage leaves, washed and dried (approx. 2 inch)
• 1/4 cup water
• squeeze of lemon
• 1/2 cup sugar
• 2 tablespoons salted butter, at room temperature
• unsalted butter for greasing the pan

For the Cake

• 1 cup cake flour
• 1/4 cup corn flour
• 1 1/4 teaspoon baking powder
• 1/4 teaspoon kosher salt
• 1/2 cup whole milk
• 2 tablespoons crème fraiche
• 1 teaspoon vanilla
• 1 stick unsalted butter, at room temperature
• 3/4 cups plus 2 Tablespoons sugar
• 2 large eggs, at room temperature
• 1 large egg white, at room temperature

1. Preheat oven to 350° F. Butter the bottom and sides of a 9 inch cake pan. Line the bottom of the pan with a parchment round and butter the top of the paper.
2. Halve and core the apple. Cut apple into 1/4 inch slices, as uniform as possible. Lay apple slices in your prepared pan, slightly overlapping. Arrange last pieces as desired in center.
3. In a mini-prep processor, pulse 2 T of walnuts and sage leaves until walnuts are a mixture of fine pieces with chunks, and the sage is finely chopped. Add remaining walnuts and pulse a few more times. You want the walnuts to be varied in texture. Spoon walnut sage mixture over apples.
4. Make caramel by putting water and squeeze of lemon (1/4 t) into saucepan. Mound sugar in the middle. Cover and bring mixture to a boil, swirling pan occasionally. Once sugar dissolves, mixture will bubble vigorously. After about 10 minutes, mixture should be fragrant and amber. Remove from heat and whisk in salted butter, 1 T at a time (be careful, mixture will be bubbling!). Carefully pour caramel over prepared apples. Allow to cool.
5. In a small bowl, thoroughly whisk cake flour, corn flour, baking powder and salt. Set aside.
6. Combine milk, crème fraiche and vanilla in a small bowl (I used my one cup measure). Set aside.
7. Using a hand mixer, cream butter for 3 minutes, scraping down sides with spatula as necessary. Add sugar all at once and continue to mix and scrape, for another 3 minutes. Add whole eggs, one at a time, mixing in between. Continue to mix and scrape for another minute.
8. Alternating between the flour mixture and the milk mixture, add to batter in three additions, mixing on low after each. Be careful to only mix until blended - do not over mix.
9. With clean beaters, whip egg white until you have soft peaks. Fold into batter in two additions. Pour batter into cake pan, smoothing evenly with a spatula. Bake until fragrant, golden brown and when poked with a tester it comes out clean, about 35 minutes.
10. Allow cake to cool before inverting onto a serving plate. Enjoy!
11. Note: Cake may be made one day ahead and stored in an airtight container.