Napoleons

Ingredients (11)

• + 1 ½ (17.5 ounce) packages frozen puff pastry sheets, thawed add to pantry
• + ¼ cup cornstarch add to pantry
• + 4 cups milk, divided add to pantry
• + ⅓ cup cake flour add to pantry
• ✓ ⅞ cup white sugar, divided
• ✓ 3 eggs, separated
• + 1 tablespoon butter add to pantry
• + 1 teaspoon vanilla extract add to pantry
• + 1 (12 ounce) jar apricot jam add to pantry
• + 3 cups sifted confectioners' sugar add to pantry
• ✓ 1 tablespoon lemon juice