Into a large bowl, place flour, butter and margarine.
Using your hands or a butter cutter, mix everything together, until the mixture resemblance small crumbles.
Mix in sour cream, baking soda and egg yolks. Mix until the dough is just combined, do not over mix.
Whip egg whites together with sugar, until the texture is thickened.
Divide dough into 7 large or 12 smaller pieces. 12 pieces will yield two smaller cakes. Roll the pieces into thin layers. Using a shape of your choice, I used a lid from a pot, cut through the dough. Apply 1/4 of an inch of meringue and sprinkle with nuts. Bake at 350F for about 10 minutes or until golden brown.
Cream for Napoleon
For the cream, whip cold heavy whipping cream until it creates soft peaks.
Using a separate dish, whip room temperature butter together with dulce de leche.
Using a spatula, fold in whipping cream with the butter cream.
To form the cake, apply small amount of cream to the plate and put a first layer on it, you don't want for the cake to slide around. Apply cream in between each layer, flat sides are easier to apply cream to.
Once finished with the last layer, place meringue on the inside.
Using you fingers, slightly press on the cake. Apply the rest of the cream to the outside.