Mixed Berry Napoleons

Ingredients

• 1 sheet frozen puff pastry
• 2 eggs, beaten
• 1/2 cup granulated sugar
• 1 tablespoon butter
• 3 tablespoons all-purpose flour
• 1 teaspoon vanilla
• 1/4 teaspoon salt
• 3 cups mixed berries, cut into smaller pieces if too big
• 2 cups milk
• 2 cups sweetened whipped cream for garnish