<b> For the Pecan Pie Cake </b>
Preheat oven to 350 degrees F. Grease (3) 9" cake pans. Evenly sprinkle with 2 cups of chopped pecans.
In a large bowl cream butter, and sugar until light and fluffy. Add in egg yolks ,vanilla, and baking soda.
Gradually add flour a little at at a time alternating with buttermilk as needed. Mix until just combined.
In a separate bowl beat egg whites until stiff peaks form. Fold egg whites and remaining pecans into cake batter.
Evenly divide batter between 3 prepared pans. Bake for 18-23 minute, or until a toothpick inserted in the center comes out clean. Cool in pan for 5 minutes, before removing.
In small bowl, combine caramel sauce and light cream. Brush over warm cakes twice. Cool completely.
<b> For the Pecan Pie Filling </b>
In a large saucepan combine brown sugar, cornstarch, egg yolks, egg, light cream, and corn syrup.
Stir constantly over medium high heat. Bring to boil, and boil for 1 minute. Remove from heat, and stir in butter & vanilla. Cool for 20 minutes, stirring at 5 minute intervals. Cool completely.
<b> Putting It All Together </b>
Place first cake layer onto a serving plate with pecans facing up. Top with half of the pecan pie filling. Repeat. Top with final cake layer.
In a large bowl whip cream and powered sugar until stiff peaks form. Spread cake with frosting, and top with additional pecans if desired.