Preheat your oven to 160°C (320°F). Prepare a 9-inch springform pan by greasing it lightly and wrapping the outside with aluminum foil to prevent water from seeping in during baking.

In a medium bowl, combine the crushed digestive biscuits and melted butter. Mix until the crumbs are evenly coated and resemble wet sand.

Press the biscuit mixture firmly into the bottom of the prepared springform pan to create an even layer. Use the back of a measuring cup or your hands to ensure it's compact.

In a large mixing bowl, beat the softened cream cheese with an electric mixer until smooth and creamy, about 2-3 minutes. Scrape down the sides of the bowl as needed.

Add the granulated sugar, sour cream, lemon juice, lemon zest, and vanilla extract to the cream cheese. Beat until fully combined, ensuring no lumps remain in the mixture.

Add the eggs one at a time, mixing on low speed after each addition just until incorporated. Be careful not to overmix, as this can introduce air bubbles that may cause cracking.

Pour the cheesecake filling over the prepared crust in the springform pan, smoothing out the top with a spatula.

Place the springform pan into a larger baking dish and fill the dish with hot water until it reaches halfway up the sides of the springform pan. This water bath helps to regulate the temperature while baking.

Bake in the preheated oven for 50-60 minutes, or until the edges are set but the center is still slightly jiggly. Turn off the oven and crack the door, allowing the cheesecake to cool slowly for about an hour.

Remove the cheesecake from the oven and the water bath. Let it cool to room temperature before transferring it to the refrigerator. Chill for at least 4 hours, preferably overnight, to allow the flavors to meld and the texture to set.

Once chilled, carefully remove the sides of the springform pan. Slice and serve your lemon cheesecake as is or with a dollop of whipped cream or a raspberry sauce for added flair.