New Orleans Doberge Cake | Saveur

Ingredients

• 1 ¹⁄₄ cups plus 2 tbsp sugar, divided
• 2 tbsp. plus 2 1/2 tsp. constarch, divided
• 1 tbsp. cocoa powder
• 1 ¹⁄₂ tsp. kosher salt, divided
• 5 large eggs, divided, plus 5 large egg yolks, divided
• ³⁄₄ cup heavy cream
• 1 ³⁄₄ cups whole milk, divided
• 1 vanilla bean, halved, each half split and seeds scraped
• 4 oz. (70 percent) dark chocolate, finely chopped
• 6 tbsp. unsalted butter, divided, cubed, plus 1 lb. (4 sticks) softened
• ¹⁄₄ cup lemon zest
• ¹⁄₂ cup lemon juice
• 3 ¹⁄₂ cups (1 lb. 1/4 oz.) cake flour
• 2 tbsp. baking powder
• 1 cup buttermilk
• 1 tbsp. sour cream
• 1 tsp. vanilla extract
• 3 cups sugar, divided
• 12 tbsp. unsalted butter, softened
• 1 ¹⁄₄ tsp. kosher salt, divided
• 1 tsp. finely grated lemon zest
• 4 large eggs, separated
• 12 oz. (70 percent) dark chocolate, finely chopped
• 1 ¹⁄₂ cups heavy cream