Step 1
Preheat oven to 350°F. Grease and flour three 8-inch round cake pans.
Step 2
In a medium bowl, combine flour, baking powder, and salt.
Step 3
In a large bowl, beat butter and both sugars until light and fluffy, about 5 minutes. Add eggs, one at a time, beat well after each addition. Scrape the sides of the bowl as needed. Alternately, add flour mixture and milk to sugar mixture, beat well after each addition. Add vanilla and hazelnuts and mix until combined. Evenly pour batter into the prepared pans.
Step 4
Bake for 25-30 minutes or until a toothpick inserted in the middle of the cake comes out clean. Remove from oven and allow the cakes to cool in the pan for 5 minutes. Remove from pans and cool completely.
Step 5
Prepare the hazelnut frosting. In a large bowl, beat butter and hazelnut spread until smooth, about 2 minutes.
Step 6
Slowly add sugar, cocoa powder, heavy cream, vanilla, hazelnut liqueur, and salt and beat at low speed until combined. Scrape the sides of the bowl as needed. Increase speed to medium-high and beat until light and fluffy, about 5 minutes.
Step 7
Assemble the cake. Place one cake layer on a serving platter. Spread about 1 cup of frosting and spread evenly. Top with the second layer of cake, spread about 1 cup of frosting and spread evenly. Top with the third layer cake. Pour the remaining frosting over the cake. Cover the top and sides of the cake. Decorate with hazelnut