Strawberry Chocolate Layer Cake

INGREDIENTS

• 1 cup powdered sugar
• 2 cups boiling water
• 2 teaspoons baking soda
• 4 sticks butter, plus more for greasing
• 1/2 teaspoon salt
• 1 cup buttermilk
• 3 cups hazelnut chocolate spread, such as Nutella
• Four 1-pound boxes ripe strawberries
• 3/4 cup cocoa, plus more for dusting
• 4 cups granulated sugar
• 1 quart heavy whipping cream
• 4 cups all-purpose flour
• 1/2 cup granulated sugar
• 2 teaspoons vanilla extract
• 2 tablespoons vanilla extract
• 4 whole eggs, beaten