Pineapple Upside Down Cake

Pineapple Upside Down Cake
1/4 cup butter
1/4 cup coconut oil
1 cup packed, dark brown sugar
1 16 ounce can pineapple slices, drained
 1/3 cup black cherries
4 eggs, separated
2 tsp. vanilla
1/2 tsp. each lemon, orange and/or almond extract
1/8 tsp. salt
1/2 C. granulated sugar 
1/2 C. unbleached all purpose flour
1/4 C. ground almond meal 
1 tsp. baking powder
Preheat the oven to 350 degrees.
Melt butter and coconut oil in 10-12 in. diameter cast iron skillet. Remove 1 Tbs. of the melted butter/oil and set aside. Add brown sugar to skillet and stir until blended. Place pineapple and cherries on top in one layer. Set aside.

In a bowl, whisk egg yolks, reserved butter/oil and extracts. Set aside. 

Beat egg whites with salt until stiff peaks form. Fold in  sugar, 2 Tbs. at a time. Fold in the egg yolk mixture.
Sift flour and baking powder together, then add in almond meal. Carefully fold it into the egg mixture in three batches.
Pour batter over pineapple and cherries, and smooth level.

Bake until a cake tester inserted in the center, comes out clean, about 30 minutes.