Part 1: Creating the Perfect Crust

1. Crush the Biscuits: Place the digestive biscuits in the bowl of a food processor and pulse until they are fine crumbs. If you don’t have a food processor, place the biscuits in a large, sealed zip-top bag and crush them with a rolling pin. Aim for a texture similar to coarse sand.
2. Combine Crust Ingredients: Transfer the biscuit crumbs to a medium-sized bowl. Add the granulated sugar and the pinch of salt, and stir to combine. Pour the melted butter over the crumb mixture.
3. Mix Thoroughly: Using a fork or your fingertips, mix until all the crumbs are evenly moistened with butter. The mixture should resemble wet sand and hold together when you pinch a small amount.
4. Press into the Pan: Tip the buttery crumb mixture into your prepared baking pan. Use the flat bottom of a measuring cup or a glass to press the crumbs down firmly and evenly across the entire base of the pan. Pay special attention to the corners and edges to create a solid foundation.
5. Pre-Bake the Crust: Place the pan in the preheated oven and bake for 10-12 minutes. The crust should be lightly golden and fragrant. This step, known as blind baking, helps to create a crispier crust that won’t get soggy from the filling. Once baked, remove the pan from the oven and set it on a wire rack to cool while you prepare the filling.

Part 2: Mixing the Creamy Filling

1. Beat the Cream Cheese: In the large bowl of a stand mixer fitted with the paddle attachment, or in a large bowl using a handheld electric mixer, place the room temperature cream cheese. Beat on medium-low speed for 2-3 minutes until it is completely smooth, creamy, and free of any lumps. Scrape down the sides and bottom of the bowl frequently to ensure everything is incorporated. Starting with smooth cream cheese is the secret to a smooth final product.
2. Add the Condensed Milk: With the mixer still on low speed, slowly pour in the can of sweetened condensed milk. Continue to beat until it’s fully combined and the mixture is smooth, about 1 minute. Scrape the bowl again.
3. Incorporate Eggs One by One: Add the eggs one at a time, beating on low speed for about 15-20 seconds after each addition, just until the yolk is broken and incorporated. Do not over-beat the batter once the eggs are in! Over-mixing incorporates too much air, which can cause the cheesecake to puff up in the oven and then crack as it cools.
4. Add Flavorings: Finally, add the lemon juice and vanilla extract. Mix on low speed for another 20-30 seconds, just until combined. Give the bowl one final scrape-down and a gentle fold with a spatula to make sure no pockets of unmixed ingredients are hiding at the bottom. The final batter should be thick, smooth, and glossy.
5. Assemble and Bake: Pour the cheesecake filling over the pre-baked crust in the pan. Use an offset spatula or the back of a spoon to spread it into an even layer, making sure it reaches all the corners.
6. Bake the Cheesecake: Place the pan back into the 160°C (320°F) oven. Bake for 35-45 minutes. The cheesecake is done when the edges are set and slightly puffed, but the center still has a slight wobble (like a gentle Jell-O jiggle) when you gently nudge the pan. It will continue to set as it cools. Be careful not to over-bake, as this can lead to a dry texture and cracks.
7. Cool Down Slowly: Turn off the oven, but do not remove the cheesecake. Prop the oven door open with a wooden spoon and let the cheesecake cool down slowly in the oven for 1 hour. This gradual cooling process is another key step in preventing cracks.
8. Chill to Perfection: After an hour, remove the cheesecake from the oven and let it cool completely to room temperature on a wire rack. Once at room temperature, cover the pan loosely with plastic wrap (don’t let it touch the surface) and transfer it to the refrigerator. Chill for at least 6 hours, but overnight is best. This chilling period is essential for the cheesecake to fully set and for the flavors to meld and deepen. Do not rush this step!