Preheat oven to 350F. Lightly grease a9x13 pan and set aside. In a large bowl, beat butter and sugar until combined. Add eggs and vanilla and mix until light and creamy.

In a medium bowl, whisk together flour, soda, salt, cinnamon and nutmeg. Add dry ingredients to wet batter and mix until just combined and a few dry streaks remain. The batter will be very stiff but will thin out after the apples are stirred in. Stir in grated apple with any accumulated juice and mix until combined. Do not overmix. Spread batter evenly in  prepared pan. Bake 30 minutes until a toothpick inserted in the center comes out clean.

Vanilla Cream Sauce While cake is baking, combine butter, cream, and sugar in a small saucepan. Bring mixture to a low simmer and stir until sugar is dissolved and mixture is combined. Simmer gently 10 minutes, stirring often. Remove from heat, stir in vanilla and keep warm until ready to serve. Cut warm cake into pieces and drizzle with warm sauce.