Preheat oven to 350º. Combine flour, baking powder, salt and spices; set aside. In mixer, combine butter and ⅔ c sugar, beating 5 min, until creamy. Add vanilla and eggs, one at a time. Add yogurt, buttermilk and applesauce, mixing briefly. Add flour mixture to wet ingredients, mixing just until combined. Pour into lightly greased 9” springform pan or cake pan, with bottom lined with parchment paper. Cut sides (faces) off of apples around core. Slice each apple face thinly, keeping intact. Press sliced apple faces into cake about halfway, slightly spaced apart (you may not need all). Sprinkle apples with a pinch of sugar and pecans. Bake cake until set and apples are soft when pierced with a pick, approx. 45-55 min. Cool on rack in pan. Remove from pan and drizzle with caramel sauce before serving.
* To make this recipe gluten-free friendly, use gluten-free flour.