½ cup brown sugar (I prefer the dark brown variety)
3 cups ½-inch cubed, cleaned pineapple (you’ll need about ¾ of a medium) OR 3 cups (about 1 pound) fresh or IQF raspberries, black berries, blueberries or pitted cherries OR 3 cups cubed, cleaned apple, pear, peaches, nectarines or mango (1/2-inch cubes are good)
¾ cup all-purpose flour
¾ cup whole wheat flour (or additional all-purpose flour)
½ teaspoon salt
¼ teaspoon baking soda
1 teaspoon baking powder
¾ cup white sugar
1 “large” egg
¾ cup buttermilk or plain yogurt
Directions
Turn on the oven to 375 degrees. Melt the butter in a 10-inch skillet (preferably non-stick) with an ovenproof handle over medium heat. Swirl the butter in the skillet until it turns nut-brown, then pour it into a large bowl. Without wiping out the skillet, sprinkle the brown sugar evenly over the bottom. Top with an even layer of the fruit.
In another large bowl, whisk together the flours, salt, soda and baking powder. Add the white sugar to the browned butter and whisk until thoroughly combined. Whisk in the egg, then the buttermilk or yogurt. Pour the wet ingredients into the bowl with the dry ones. Whisk to thoroughly combine.
Pour the batter evenly over the fruit in the skillet. Slide the skillet into the oven and bake 25 to 30 minutes, until the cake is golden brown and springy to the touch at the center. Remove and let cool 10 minutes. Invert a plate over the skillet, then, holding plate and skillet firmly together with towels or pot holders, invert the two in one swift movement. Remove the skillet and the cake is ready to serve. It’s best right out of the oven.