Preheat oven to 350℉ and spray an 8 inch spring form pan with non stick spray.
Apple & Walnut Topping
In a medium sized bowl mix together ingredients for apple and walnut topping. Set aside.
In a separate large sized bowl sift together dry ingredients for the cake. Stir in spices. Set aside.
In another large sized bowl thoroughly mix together yogurt, eggs, oil and sugar. Pour into flour mixture for cake and mix until just incorporated. Pour into springform pan and evenly spread batter with bowl scraper. Pour apple and walnut mixture evenly over top of cake.
Bake for 80-90 mins or until a toothpick inserted into center comes out clean. Let cool until just above room temperature.
While cake is cooling add brown sugar, butter and milk to a small saucepan and place over medium/low heat. Stirring occasionally bring to a gentle boil for 2 full mins. Take off heat and stir in vanilla. Let cool slightly to almost room temperature still stirring occasionally.
Once cake has cooled just above room temperature pour desired amount of caramel over cake reserving extra for slices. Serve while still warm. Store at room temperature loosely covered.
*Please use as many organic ingredients as possible.*