Ooey Gooey Butter Layer Cake

INGREDIENTS

• 3 1/2 cups all-purpose flour, plus more for dusting
• 1 tablespoon vanilla extract
• 6 cups confectioners' sugar
• 1 cup sour cream
• 1/3 cup orange juice
• One 8-ounce package cream cheese, softened
• 1/4 teaspoon salt
• 2 1/4 cups granulated sugar
• 3/4 cup granulated sugar
• 1 teaspoon vanilla extract
• 1 tablespoon baking powder
• 5 large eggs
• 1 stick (1/2 cup) unsalted butter, softened
• 3 large eggs
• 1 stick (1/2 cup) unsalted butter
• One 8-ounce package cream cheese, softened and cubed
• 1/2 teaspoon baking soda
• 3 sticks (1 1/2 cups) unsalted butter, softened, plus more for greasing
• 1 1/4 cups buttermilk
• Butter Filling, for assembling, recipe follows