Make crumb crust as directed. Preheat oven to 350°F.

Beat cream cheese with an electric mixer until fluffy and add eggs, 1 at a time, then vanilla and sugar, beating on low speed until each ingredient is incorporated and scraping down bowl between additions.

Put springform pan with crust in a shallow baking pan. Pour filling into crust and bake in baking pan (to catch drips) in middle of oven 45 minutes, or until cake is set 3 inches from edge but center is still slightly wobbly when pan is gently shaken. Let stand in baking pan on a rack 5 minutes. Leave oven on.

Stir together sour cream, sugar, and vanilla. Drop spoonfuls of topping around edge of cake and spread gently over center, smoothing evenly. Bake cake with topping 10 minutes.

Run a knife around top edge of cake to loosen and cool completely in springform pan on rack. (Cake will continue to set as it cools.) Chill cake, loosely covered, at least 6 hours. Remove side from pan and transfer cake to a plate. Bring to room temperature before serving.