Best Ever Cheesecake

Preheat oven to 375°F (190°C).

Melt butter and combine with graham cracker crumbs. Cover the bottom of a 9-inch springform pan; set aside. Beat egg whites until stiff; set aside.

In a large mixing bowl, combine cream cheese, egg yolks, 3/4 cup sugar and vanilla. Beat until smooth (there should be no granular feeling to the batter). Fold in the beaten egg whites. Gently transfer to prepared pan. Bake for 40 to 50 minutes or until center is almost set. (A small area in the center may still appear moist and jiggly; this will set up while the cheesecake is cooling.)

Just before cooking time has elapsed, whisk together sour cream and remaining 1/4 cup sugar until smooth. Remove cheesecake from oven, turn temperature up to 425°F (220°C) and pour sour cream mixture evenly on top. Return cheesecake to oven for 5 to 7 minutes. Remove from the oven and cool completely before removing it from the pan.