Butter-Toasted-Walnut Layer Cake

Ingredients

• 2 cups shelled and chopped walnuts
• 3 cups unbleached all-purpose flour
• 1-1/4 cup unsalted butter, divided and at room temperature
• 2 teaspoons baking powder
• 2 cups granulated sugar
• 4 large eggs
• 1/2 teaspoon salt
• 2 teaspoons pure vanilla extract
• 6 tablespoons unsalted butter at room temperature
• 6 cups icing sugar
• 1 cup 2% milk
• 1 teaspoon pure vanilla extract
• 30 (approximately) walnut halves, for decoration
• 6-9 tablespoons evaporated milk

 Preparation: 

1. Firstly, Preheat oven to 350°F. Grease three 8-inch round cake pans, covering the bottoms with parchment paper, greasing the paper lightly as well. 
2. Dust greased pans with flour. Set aside. Spread chopped walnuts over a large baking sheet. Melt 1/4 cup of butter and drizzle over nuts, then stir so all pieces are lightly coated. Bake for fifteen to twenty minutes, stirring frequently, until nuts are well browned. 
3. Remove baking sheet from oven and slide nuts into a bowl to cool. Reserve. In a medium mixing bowl, sift together flour, baking powder, and salt. Set aside. With a mixer, cream the butter. With beaters running, add sugar gradually until mixture is pale yellow and fluffy. 
4. Break eggs one after another into a small bowl; break the yolks with the tines of a fork before adding to the cake batter, beating well after each addition. Stir in vanilla extract. Blend dry ingredients into batter alternately with the milk, beginning and ending with dry ingredients, and mixing well after each addition. Add cooled roasted walnuts to batter, stirring just to combine. 
5. Divide batter evenly between the three cake pans and bake in the center of the preheated oven for twenty–to twenty-five mins. Test cakes beginning at the 20-minute mark and remove as soon as a tester inserted into the center of each cake comes out clean. Cool cakes and frost as directed below.
6.  For frosting, cream together butter and sugar in a mixer. Add the vanilla and evaporated milk until the mixture is of spreading consistency. If needed, dribble in more evaporated milk or sprinkle in more icing sugar as necessary to achieve the right consistency. Frost in between each cake layer and then over the top and down the sides of the assembled cake. 
7. Decorate outer top edge of cake with walnut halves.