Preheat oven to 350°F. Stir together graham crumbs, 1/4 cup sugar, and melted butter until cohesive. Press firmly into an ungreased 13x18-inch rimmed baking sheet.

Bake the crust 10 minutes until fragrant. Remove from oven, reduce heat to 325°F.

Beat cream cheese until smooth, about 2 minutes. Add 1 1/4 cups sugar and beat until fluffy. Mix in eggs one at a time on low, then vanilla and sour cream just until combined.

Pour filling over crust, spread even, and tap the pan to release air bubbles. Bake at 325°F for 25 to 30 minutes, until edges are set and center jiggles softly. Turn off oven, crack the door open, and let the cheesecake cool inside for 1 hour. Remove from oven, cool completely at room temperature, then cover and refrigerate at least 4 hours.

Run a knife around the pan edge. Slice into 24 squares. Serve cold with strawberry sauce or fresh berries.