Apple Custard Pie with Cinnamon Streusel

Bahan-bahan (8 porsi)

• 1 pie crust (9 inch)
• 5 large apples (**)
• 1/2 lemon
• 4 tablespoons butter (1/2 stick )
• 1/2 cup white sugar
• 1 tablespoon pumpkin pie spice
• 1 & 1/3 cup sour cream (+ 1 tablespoon)
• 5 large egg yolks (not the whites)
• 1 & 1/2 teaspoons vanilla
• 1 & 1/2 cups white sugar
• 6 tablespoons flour
• 1/2 cup flour
• 1 tablespoon pumpkin pie spice
• 1/4 cup white sugar
• 4 tablespoons butter (cold, cut into chunks)