First, prepare your baking pan. Grease a 12 cup bundt pan generously with shortening and flour. To make things easier, you can also easily use Baker’s Joy nonstick cooking spray for baking. Set aside and preheat your oven to 350F.
In a large bowl, add your butter and beat until creamy with an electric mixer. Once the butter has reached a creamy and smooth consistency, be sure to scrape down the sides of the bowl, the add in the sugar. Beat the sugar and butter together until thoroughly combined, about 1-2 minutes and set aside.
In a separate mixing bowl, add together the eggs, egg yolks, vanilla extract, and salt. Use a fork or whisk to beat the eggs and yolks together and ensure that the salt and vanilla are evenly mixed in. With an electric mixer on low, slowly begin to add your egg mixture into your sugar and butter mixture. Allow the egg mixture to be fully incorporated into the batter before continuing to add more of the egg mixture. Once the egg mixture has been thoroughly combined, scrape down the sides of the bowl and beat the batter on medium high for about 2-3minutes. Reduce the electric mixer back to low, then slowly add in the flour, continuing to scrape down the sides of the bowl until all of the flour has been incorporated. Stir the entire mixture on medium-speed and beat for an additional minute. Pour the batter into your greased 12 cup bundt cake pan.
Bake the cake for about an hour and 10-20 minutes. Use a wooden skewer and insert into the thickest part of the cake to determine doneness. Once baked, all the cake to cool for at least 20-25 minutes. Once the cake has cooled, insert a knife around the sides of the pan. Place the cake on a cooling rack and continue to allow to cool. Once cooled completely, slice and serve with fresh berries and whipped cream.