S'more Icebox Cake

Ingredients

• 2 ¼ cup all-purpose flour
• 1 ½ cup whole-wheat flour
• 1 ½ teaspoon baking soda
• rounded 1 teaspoon salt
• 5 tablespoon whole milk
• 1 ½ teaspoon pure vanilla extract
• rounded 1 cup packed dark brown sugar
• 5 tablespoon unsalted butter, at room temperature
• ¼ cup vegetable oil
• 1/3 cup honey
• crushed graham crackers or grated chocolate for decorating
• 1 cup granulated sugar
• ½ cup dutch-process cocoa powder
• ¼ cup cornstarch
• ¾ teaspoon salt
• 2 ½ cup whole milk
• ¾ cup heavy cream
• 1 egg, lightly beaten
• 1 tablespoon unsalted butter, at room temperature
• 2 teaspoon pure vanilla extract
• 3 egg whites, at room temperature
• ¾ teaspoon cream of tartar
• ¼ teaspoon salt
• 1 tablespoon granulated sugar, plus ¾ cup
• ¾ cup light corn syrup
• ¼ cup water
• ¾ teaspoon pure vanilla extract
• 2 cup heavy cream
• nonstick cooking spray