Make the cake: Preheat oven to 350F (175C). Line three 8-inch round cake pans with parchment and, grease with butter and dust with flour. set aside.
In a large bowl whisk eggs and sugar, until doubled in volume, about 5-6 minutes. in a separate bowl stir sour cream with baking soda, then add to the egg mixture and beat until incorporated. Add dulce de leche or caramel sauce and beat until incorporated.
Sift flour, baking powder and salt. Stir until incorporated. Do not overmix.
Divide the butter between the pans. Bake for 16-18 minutes, or until a toothpick inserted in the center comes out clean. Remove from the oven and let cool for 5-10 minutes, release from the pan and let cool completely. then, cut the tops of the cakes. Cut into small cubes and bake at 400F (200C) for 10 minutes, until golden brown. Set aside for later.
Make the syrup: in a small saucepan heat water, milk, sugar, coffee and liquor. Bring to a simmer until the sugar is dissolved, set aside.
Make the cream: in a large bowl beat butter until cream cheese until smooth. Add dulce de leche or caramel sauce and beat until incorporated and smooth. In a separate bowl neat heavy cream to medium peaks. Fold the whipped cream into the butter mixture. Transfer to a piping bag (optional).
Assembly: place first cake layer (cut side up) in the middle of the platter, soak with the syrup. Spread/pipe a layer of the cream, sprinkle 1-2 tablespoons of crushed hazelnuts. Repeat: place the second layer of cake, soak with syrup, spread another layer of cream, sprinkle hazelnuts. Place third layer of cake (cut side down), soak with syrup. Spread the remaining cream over top and the sides of cake. Using caramel sauce/dulce de leche create the design on top of the cake as shown in the video.
Place baked leftover cake pieces in a food processor and process into small crumbs. Decorate the cake with the crumbs.
Can I use store-bought caramel sauce for this recipe?
Yes, you can use store-bought caramel sauce for convenience. However, homemade caramel sauce will provide the best flavor.
Can I make this cake in advance?
Yes, you can bake the cake layers in advance and store them in an airtight container at room temperature for up to 2 days. You can also prepare the cream and syrup ahead of time and assemble the cake before serving.
Can I substitute sour cream with another ingredient?
You can substitute sour cream with an equal amount of Greek yogurt for a similar texture and flavor.
Do I have to use liquor or rum in the syrup?
No, the liquor or rum is optional. You can omit it if you prefer.
Can I use a different type of nut for the hazelnut topping?
Yes, you can use any nut you like or omit the nuts altogether if you have allergies or prefer a nut-free option.
How should I store the leftover cake?
Store any leftover cake in an airtight container in the refrigerator for up to 3 days.
Can I freeze this cake?
Yes, you can freeze the assembled cake for up to 1 month. Thaw in the refrigerator overnight before serving.
Can I use a different size cake pan?
You can use different size cake pans, but the baking time may vary. Adjust the baking time accordingly and check for doneness with a toothpick.
Can I use a different type of frosting?
Yes, you can use a different frosting if you prefer. However, the caramel cream frosting complements the cake's flavors well.