½ cup (1 stick) unsalted butter
½ cup light-brown sugar
2 cups fresh blueberries or other seasonal fruit
1 cup gluten-free or regular baking flour
½ cup almond flour
½ cup coconut flour
1 Tbs. baking powder
1 tsp. salt or salt substitute
1½ cups Xylitol or sugar
1 cup cubed and slightly softened unsalted butter
2 tsp. vanilla extract
4 large eggs (organic, free-range, or Omega-3-enriched), separated
¾ cup plain yogurt
Preheat the oven to 350 degrees.
Make the topping: In a saucepan or 10-inch cast-iron skillet, melt the butter over medium heat. Add the sugar, stir, and cook for 2–3 minutes or until well mixed.
Pour the mixture into a 10-inch round cake pan (or leave in skillet if oven-proof) and spread evenly with a spatula.
Lay the fresh fruit over the mixture evenly and set the pan aside.
Make the cake batter: In a large mixing bowl, mix the flours, baking powder, and salt and set aside. In a stand mixer with paddle attachment, beat the xylitol or sugar and butter until fluffy. Mix in the vanilla extract. Blend in the eggs one at a time. Gradually add the flour mixture and blend thoroughly. Slowly fold in the yogurt.
Spoon the batter evenly over the fruit in the pan and bake on the middle oven rack at 350 degrees for 40–45 minutes or until a toothpick inserted in the center comes out clean.
Allow to cool for 10–15 minutes. Run a knife along the inside the edge of the cake pan while it is still warm to loosen it.
Cover the cake pan with a plate or large tray and turn it upside-down to invert the cake onto the plate.
Chef’s Note: If you’re using another type of fruit, be sure to peel, slice, and de-seed it if needed. The slices should be about ¼-inch thick.