Caramel Apple Layer Cake with Apple Cider Frosting

2 cups whole wheat pastry flour
1 3/4 cups all-purpose flour
1 tbsp baking powder
1 1/2 tsp baking soda
1 1/2 tsp ground cinnamon
1/2 tsp salt
1 1/2 cups light brown sugar
3/4 cup canola oil
3/4 cup unsweetened applesauce
3/4 cup caramel sauce (homemade or jarred)
2 tsp vanilla extract
3 eggs
1 1/2 cups buttermilk
Apple Cider Frosting:
7 1/2-8 cups confectioners sugar (to desired consistency)
3/4 cup butter, softened
1/2 cup apple cider or apple juice
3/4 tsp ground cinnamon
pinch of salt

• Preheat oven to 350°F. Grease and flour 2 (8 or 9 inch) round cake pans and set aside
• In a large bowl, whisk together whole wheat pastry flour, all-purpose flour, baking powder, baking soda, cinnamon and salt. 
• Set aside. 
• In a second large bowl, beat sugar and oil together with an electric mixer until well combined, about 30 seconds. 
• Add applesauce, caramel and vanilla, beat for 30 seconds, then add eggs one at a time, beating well after each addition. 
• Add flour mixture in 3 parts, alternating with the buttermilk, and continuing to beat until well combined.
•  Pour batter into prepared cake pans and bake until golden brown and a toothpick inserted in the middle of each cake comes out clean, about 35-40 minutes.
• Set aside to let cool for 10 minutes, then gently loosen cakes and turn out onto a cooling rack; set aside to let cool completely.
• For the frosting, put sugar, butter, coder, cinnamon and salt into a large bowl and beat with an electric mixer until light and fluffy, about 5 minutes. 
• Arrange one cake on a large plate and spread about 1 cup of the frosting evenly over the top. 
• Arrange second cake on top then frost top and sides of entire cake with remaining frosting.
• Set aside at room temperature or in the refrigerator for at least 1 hour to allow frosting to set before serving.