Butter and flour 3 six inch cake pans. (I always wrap mine in cake strips)
In a mixing bowl, beat together the eggs, sugar, oils, sour cream, vanilla and pumpkin.
Sift together the flour, baking powder, salt, baking soda, salt and spices; add to wet ingredients and mix thoroughly.
Spread into prepared pans.
Bake for approximately 25 minutes or until centers firm up.
For the Pecan Sauce:
Preheat the oven to 350 degrees. Place the pecans on a baking sheet and bake for about 8-10 minutes or until lightly browned and fragrant. Remove from oven, cool, and then chop fairly fine.
In a medium saucepan, combine the sugar, milk, egg yolks, butter, and salt. Cook over medium heat, stirring constantly, and when the mixture begins to boil and thicken, remove from heat (about 5 minutes). Stir in the chopped pecans, and vanilla extract. Let cool until spreadable (about 30-60 minutes).
For the Vanilla Buttercream:
Whip the butter for about 5 minutes, using a paddle attachment (stand-up mixer).
Beat in the confectioner’s sugar slowly.
Add the cream and vanilla. Beat until you have an even, fluffy consistency.
For the Assembly:
Pipe a circle of vanilla buttercream along the perimeter of the cake. Use an ice cream scoop to add pecan frosting to the center of buttercream circle. Do this between each layer.
Cover the cake with a thin crumb coat.
Cover the cake with the buttercream and smooth with an offset spatula.
Using a large closed star tip, pipe dollops around the top of the cake.
Scoop pecan frosting into the middle circle.
Add toasted pecans to the bottom.
Notes: You could use the extra batter for about 6 cupcakes