Step 1: Preheat your oven to 325°F (160°C). Grease a 9-inch springform pan and wrap the outside tightly with heavy-duty aluminum foil to prevent water from entering during the water bath.
Step 2: Combine graham cracker crumbs, 1/4 cup sugar, and melted butter in a bowl. Press the mixture firmly into the bottom of the prepared pan. Bake for 10 minutes, then set aside to cool.
Step 3: In a large bowl, beat the softened cream cheese and 1.25 cups sugar until completely smooth and creamy, about 3 minutes. Scrape down the sides of the bowl as needed.
Step 4: Add the sour cream, vanilla, orange zest, and orange juice. Mix on low speed until just combined.
Step 5: Add the eggs one at a time, mixing on low speed after each addition just until the yellow disappears. Do not overmix.
Step 6: Pour the batter over the cooled crust. Place the springform pan into a larger roasting pan and fill the roasting pan with hot water until it reaches halfway up the sides of the cheesecake pan.
Step 7: Bake for 70-80 minutes, or until the edges are set but the center still has a slight jiggle. Turn off the oven, crack the door slightly, and let the cheesecake cool inside for 1 hour.
Step 8: Remove from the water bath, take off the foil, and refrigerate for at least 6 hours or overnight before serving.