Preheat oven to 350°F.

Brush 3 (9-inch) round pans with melted butter and line with parchment paper. Brush with more butter. You could also use non-stick cooking spray. Set aside.

In a medium bowl, measure out flour, baking powder and salt. Whisk together. Set aside.

In a large bowl, cream butter with an electric mixer until smooth. Add sugar and mix. Add eggs and mix until combined. Add half of the flour mixture and half of the milk, plus the vanilla. Mix on medium low until combined. Repeat with remaining flour and milk. Mix until combined, then continue mixing on medium low for 30 seconds. Divide batter between the three prepared pans. Bake on the middle rack of your oven for 20-25 minutes. At 20 minutes, test one of the cakes by inserting a toothpick. If it comes out clean, they are done. If not, continue to bake for just a few minutes more. Let cool completely,

In a large bowl, cream butter and cream cheese with an electric mixer until smooth. Gradually add the powdered sugar with the mixer on low. Once it's added, turn mixer up to medium high and beat until smooth. Add flavoring and mix.

Remove cakes from pans. Cut off a little bit of the top, horizontally, if there is a slight dome shape to your cakes. Place one layer on cake plate. Add frosting and 1/4 cup of nuts. Add another layer. Frost and add 1/4 cup of nuts. Add top layer. Frost top and sides of cake. Create a swirling pattern in icing, if desired, with offset spatula. Add nuts to top. Store cake, covered, at room temperature for one day and in the refrigerator for up to 5 days.