Preheat the oven to 350F/177C and line three, 8-inch (20-cm) cake pans with parchment paper; spray the sides with a baking spray.
Prepare the cake batter. In a large mixing bowl, combine the buttermilk, oil, eggs, vanilla and sugars. Beat on medium speed for 2 to 3 minutes, until the eggs are well beaten and the mixture is smooth. In a separate mixing bowl, combine the dry ingredients: flour, baking soda, baking powder, salt, cinnamon and nutmeg. Sift the dry ingredients into the batter and mix on medium speed for 1 minute, just until incorporated.
Divide the cake batter evenly between the three prepared pans and level the batter with a spoon or spatula. Bake in the preheated oven at 350F/177C for 25 to 27 minutes, until a toothpick inserted into the center comes out clean. Cool the cake layers in the pans for 5 minutes, then transfer onto a wire rack to cool completely.
For Cinnamon Cream Cheese Frosting:
Next, prepare the cream cheese frosting. Place the softened butter into a large mixing bowl and whisk on high speed for 5 minutes, until the butter is light and fluffy. Add the softened cream cheese and continue whisking for another 3 to 4 minutes, scraping down the sides of the mixing bowl often, until smooth and creamy. Add the vanilla, salt, cinnamon and confectioner’s sugar. Mix again for 2 to 3 minutes on medium-high speed until the frosting is fluffy. If the frosting is too soft, refrigerate until thickened.
For Caramel Filling:
For the caramel filling, combine the dulce de leche, cinnamon and nutmeg in a small mixing bowl. Use a spatula to fold the spices into the caramel thoroughly.
Assembling the Cake:
To assemble the cake, first make sure the layers are completely cooled. Next, use a serrated knife to level off the tops of each layer. Spread half of the prepared caramel filling onto the first cake layer and use a spatula to spread it evenly to the edges. Top the caramel with a generous amount of the cream cheese frosting. Gently spread the frosting over the caramel with an off-set spatula.
Repeat the same process for the next cake layer, using the remaining caramel filling. Top with the last cake layer, then apply a crumb coat of frosting onto the cake. Allow the cake to chill in the refrigerator for 15 to 30 minutes before applying the final layer of frosting. Watch my video recipe to see how it’s done.
To garnish the cake, transfer any remaining frosting into a pastry bag tipped with a star tip; I used a French star tip #4. Pipe dollops onto the cake and garnish with a sprinkle of ground cinnamon and a drizzle of caramel sauce. For best results, refrigerate the cake for 1 hour prior to serving.