Cake:

1. Preheat oven to 325 degrees (F).
2. Prepare four (8-inch) round cake pans with cooking spray and parchment. Set aside.
3. In a very large mixing bowl, combine the flour, baking soda and salt.
4. In another large mixing bowl, whisk together melted butter, brown sugar and granulated sugar until combined.
5. Add whole eggs and yolks one at a time, whisking after each addition until completely combined.
6. Add vanilla, stir to combine.
7. Using a large rubber spatula, fold the we ingredients into your large bowl of dry ingredients.
8. Continue to fold the mixture until all of the flour is absorbed, but do not over mix.
9. Stir in the chocolate chips.
10. Evenly divide the batter among the four baking pans, and use your fingers to press the batter and spread it to the edges of the pan.
11. Bake for 20-28 minutes or until the tops are just golden brown. Avoid overbaking – you want the middle to be soft.
12. Remove from oven and cool on wire racks until cookies are completely cool.
13. Prepare frosting.

Frosting:

1. In the bowl of a stand mixer, beat softened butter until light and fluffy.
2. Add powdered sugar, cream and vanilla, and beat until completely incorporated and smooth. Add more milk if needed.
3. Assemble the cake by placed about a cup of frosting between the bottom three layers.
4. Cover with plastic wrap and refrigerate until the frosting sets, then remove from the refrigerator.