Swiss Hazelnut Cake

FOR THE CAKE: Adjust oven rack to middle position and heat oven to 350 degrees. Line 2 light-colored 9-inch round cake pans with parchment paper; grease parchment but not pan sides.

Process hazelnuts in food processor until finely ground, about 30 seconds. Whisk flour, sugar, baking powder, salt, and ground hazelnuts together in large bowl. Whisk oil, water, egg yolks, and vanilla together in separate bowl. Whisk egg yolk mixture into flour-nut mixture until smooth batter forms.

Using stand mixer fitted with whisk, whip egg whites and cream of tartar on medium-low speed until foamy, about

1 minute. Increase speed to medium-high and whip until soft peaks form, 2

to 3 minutes. Gently whisk one-third of whipped egg whites into batter. Using rubber spatula, gently fold remaining egg whites into batter until incorporated.

Divide batter evenly between prepared pans and gently tap pans on counter to release air bubbles. Bake until tops are light golden brown and cakes spring back when pressed lightly in center, 25 to 28 minutes, rotating pans halfway through baking.

Let cakes cool in pans for 15 minutes. Run knife around edges of pans; invert cakes onto wire rack. Discard parchment and let cakes cool completely, at least 1 hour. (To prepare to make chocolate shavings, place food processor shredding disk in freezer.)

FOR THE FROSTING: Using clean stand mixer fitted with whisk, whip butter and salt on medium speed until smooth, about 1 minute. Reduce speed to low and slowly add sugar. Increase speed to medium and whip until smooth, about 2 minutes, scraping down sides of bowl as needed. Add marshmallow crème, increase speed to medium-high, and whip until light and fluffy, 3 to 5 minutes. Reduce speed to low, add hazelnut liqueur, return speed to medium-high, and whip to incorporate, about 30 seconds.

Line rimmed baking sheet with parchment paper. Fit food processor with chilled shredding disk. Turn

on processor and feed chocolate bar through hopper. Transfer shaved chocolate to prepared baking sheet and spread into even layer. Place in freezer to harden, about 10 minutes.

Place 1 cake layer on cake stand. Spread 2 cups frosting evenly over top, right to edge of cake. Top with second cake layer, pressing lightly to adhere. Spread remaining 2 cups frosting evenly over top and sides of cake.

9. Fold 16 by 12-inch sheet of parchment paper into 6 by 4-inch rectangle. Using parchment rectangle, scoop up half of chocolate shavings and sprinkle over top of cake. Once top of cake is coated, scoop up remaining chocolate shavings and press gently against sides of cake to adhere, scooping and reapplying as needed. Serve.