3 cup finely chopped pecans, toasted
2 cup flour
1 teaspoon baking soda
½ cup butter, softened
½ cup shortening
2 cup sugar
5 egg yolks
1 tablespoon vanilla extract
1 cup buttermilk
5 egg whites
¾ C. dark corn syrup
Pecan Pie Filling (recipe follows)

Sprinkle 2 cups of the chopped pecans evenly over the bottoms of 3 buttered 9-inch round cake pans, shaking to coat the bottoms and sides of the pans.

Combine the flour and baking soda in a bowl and mix well.

Beat the butter and shortening in a mixer bowl at medium speed until light and fluffy. Beat in the sugar gradually. Add the egg yolks 1 at a time, mixing well after each addition. Stir in the vanilla. Add the flour mixture and buttermilk alternately, mixing well after each addition and beginning and ending with the flour mixture. Stir in the remaining 1 cup pecans.

Beat the egg whites in a mixer bowl at medium speed until stiff peaks form. Fold 1/3 of the beaten egg whites into the batter. Fold in the remaining egg whites. Pour the batter into the prepared pans.

Bake at 350° F for 25 minutes or until a wooden pick inserted in the center comes out clean. Cool in the pans on wire racks for 10 minutes. Invert onto waxed paper-lined wire racks. Brush the tops and sides of the layers with corn syrup, Cool completely.

Pecan Pie Filling:

½ cup packed dark brown sugar
¾ cup dark corn syrup
1/3 cup cornstarch
4 egg yolks
1 ½ cup half-and-half
1/8 teaspoon salt
3 tablespoons butter
1 teaspoon vanilla extract

Whisk the brown sugar, corn syrup, cornstarch, egg yolks, half-and-half and salt in a heavy 3-quart saucepan until smooth. Bring to a boil over medium heat, whisking constantly. Boil for 1 minute or until mixture thickens. Remove from heat. Whisk in the butter and vanilla. Place a sheet of waxed paper on the surface of the mixture. Chill for 4 hours.

Place 1 cake layer pecan side up on a serving plate.  Spread with half the Pecan Pie Filling. Place the second cake layer pecan side up on the filling. Spread with the remaining Pecan Pie Filling. Place the third layer pecan side up on the filling.