Makes 1 (9-inch) cheesecake

Crust:
2 cups firmly packed vanilla wafer crumbs
1⁄3 cup sugar
6 tablespoons butter, melted
1 large egg white, lightly beaten

Filling:
4 (8-ounce) packages cream cheese, softened
1 1⁄2 cups plus 1⁄4 cup sugar, divided
6 large egg yolks
2 tablespoons all-purpose flour
1 cup sour cream

Garnish: sugared fresh raspberries

Preheat oven to 300°.

For crust: In a small bowl, combine vanilla wafer crumbs, 1⁄3 cup sugar, melted butter, and egg white, stirring to combine well. Press firmly on bottom and up sides of a 9 1⁄2-inch springform pan. Bake for 8 minutes; set aside to let cool.

For filling: In a large bowl, beat cream cheese and 1 1⁄2 cups sugar with a mixer at medium speed until fluffy. Beat in egg yolks, one at a time, beating well after each addition. Add flour, beating just until combined. Stir in sour cream. Spoon batter into prepared crust. Bake for 1 hour and 15 minutes; turn oven off. Leave in oven with door closed for 4 hours. Remove cheesecake from oven. Gently run a knife around edge of pan to release sides. Let cool completely in pan. Cover, and refrigerate for 8 hours.

Evenly sprinkle remaining 1⁄4 cup sugar on top of cheesecake. Caramelize sugar with kitchen torch until sugar is melted. Remove sides of pan to serve. Garnish with sugared fresh raspberries, if desired.