Method:
Prepare the crust:

Preheat your oven to 325°F (163°C).
In a bowl, mix the crushed digestive biscuits or graham crackers with melted butter and sugar (if using). Stir until the mixture is well combined and resembles wet sand.
Spoon the crust mixture into the bottom of 12 muffin tins (lined with paper liners) or silicone mini tart pans. Press down gently to compact the crust.
Bake the crusts for about 8-10 minutes until golden and set. Remove from the oven and allow to cool slightly.
Make the filling:

In a food processor or blender, combine the cottage cheese, cream cheese, sour cream, sugar, lemon zest, lemon juice, vanilla extract, and a pinch of salt. Blend until smooth and creamy.
Add the eggs one at a time, blending until well incorporated after each addition. The mixture should be smooth and thick.
Assemble the cheesecakes:

Spoon the cheesecake filling over the cooled crusts in the muffin tins or tart pans, filling each about 3/4 full.
Smooth the tops with a spatula to ensure even layers.
Bake:

Bake the mini cheesecakes for about 20-25 minutes, or until the filling is set and lightly golden on top. The center may still jiggle a little, but it will firm up as it cools.
Turn off the oven and let the cheesecakes cool in the oven with the door ajar for about 1 hour to prevent cracking. Then, transfer them to the fridge to chill for at least 3 hours or overnight for the best texture.