Preheat the oven to 350°F (175°C). Lightly grease the bottom and sides of a 9-inch springform pan.

Combine the graham cracker crumbs, ¼ cup sugar, and melted butter until evenly moistened. Press firmly across the bottom and about 1 inch up the sides of the prepared pan.

Bake for 10 minutes. Transfer the pan to a rack and let the crust cool while you prepare the filling. Reduce the oven temperature to 325°F (160°C).

Beat the softened cream cheese on low to medium-low speed until smooth. Add 1 ¼ cups sugar and the vanilla, then mix only until evenly combined.

Add the eggs one at a time on low speed, mixing only until each egg disappears into the batter. Stir in the lemon zest, if using. Avoid overmixing.

Pour the filling over the cooled crust and smooth the top. Wrap the outside of the springform pan securely with two layers of heavy-duty aluminum foil.

Place the wrapped springform pan inside a larger roasting pan. Carefully add hot water to the roasting pan until it reaches about halfway up the outside of the springform pan.

Bake for 60 to 70 minutes. The outer edge should look set while the center still has a gentle jiggle when the pan is lightly moved.

Turn off the oven, crack the door open, and leave the cheesecake inside for 1 hour. Remove it from the water bath and discard the foil. Cool on a rack until no longer warm, then refrigerate within 2 hours of removing it from the oven.

Cover the cooled cheesecake and refrigerate for at least 4 hours, preferably overnight, before releasing the springform ring.

For clean slices, use a thin knife warmed in hot water and wiped dry between cuts. Serve the cheesecake chilled, plain or with a topping added at serving time.