The most extraordinary moist three-layer Nutella Cake made by preheating oven to 350°F greasing and lining three 8-inch pans whisking 2 cups flour 1 1/2 cups sugar 1/2 cup cocoa 2 tsp baking powder 1 tsp baking soda and 1/2 tsp salt beating 3/4 cup softened butter and 3/4 cup Nutella medium-high 2 to 3 minutes light and creamy adding 3 room temperature eggs one at a time then 1 tsp vanilla on low alternating flour in 3 additions with 1 cup room temperature buttermilk in 2 additions just combined gently folding 1/2 cup mini chocolate chips dividing among three pans baking 22 to 25 minutes until toothpick shows few moist crumbs cooling 10 minutes then on racks then beating 1 cup room temperature butter and 1 cup Nutella until smooth adding 4 to 5 cups sifted powdered sugar alternating with cream adding vanilla and salt beating medium-high 2 to 3 minutes fluffy assembling three layers with Nutella buttercream crumb coating refrigerating 20 minutes applying final frosting pouring cooled ganache of 1/4 cup cream poured over 4 oz chips whisked smooth over top scattering toasted hazelnuts and drizzling 3 tbsp melted Nutella. A completely extraordinary hazelnut chocolate three-layer Nutella celebration cake recipe.