In a large bowl, mix together, eggs, sugar, and oil. Add cinnamon, salt, baking soda, zucchini, and pecans. Blend in flour.
Prep baking pans with spray oil and flour to prevent sticking.
Divide batter evenly between cake pans.
Bake 3750° for 35-45 minutes. Use a cake tester or toothpick to test for doneness. Cake is ready when tester or toothpick inserted into center comes out clean.
Sit pans on wire rack until cooled, approximately 20 minutes. Slide knife around edges of cake to loosen from pan. Carefully tilt pans upside down with a hand under each to catch the cake.
Use a hand or stand mixer to blend the frosting. Mix butter and cream cheese together with vanilla until creamy. Add in powdered sugar and blend on slow speed until incorporated and then beat at medium high until frosting is smooth. Do not refridgerate.
Place cakes on flat surface and use a large bread knife to cut the very top layer off of one cake until it has a flat surface.
Use the frosting piping tool to frost the cut layer of the cake, this will be the middle frosting layer, use 1/3 of the frosting for this.
Place the uncut piece of cake on top of the frosted layer.
Use a spatula to smooth a thin layer of frosting all around the cake.
Use the pipping tool to decorate the sides and top if you wish, or just keep the top smooth with another layer spread with a spatula.
Top cake with finely chopped pecans.
Store in the refridgerator for 3-4 days, if it lasts that long.