Crush the digestive biscuits into fine crumbs using a rolling pin or food processor. Transfer them into a bowl and pour in the melted butter.

Mix until all the crumbs are evenly coated and resemble wet sand.

Press the mixture firmly into a lined square pan, smoothing it into an even layer. Place it in the freezer for about 20 minutes to firm up.

In a large bowl, add the softened cream cheese and sugar. Mix until completely smooth and free of lumps.

Add the thick yogurt and mix again until fully combined and silky.

Soak the gelatin sheets in cold water until softened, then squeeze out excess water. Add them into the warm milk and stir until fully dissolved.

Pour the gelatin mixture into the cheesecake mixture and stir well.

Finally, add the fresh lemon juice and gently mix until smooth.

Pour the cheesecake filling over the chilled biscuit base. Use a spatula to smooth out the top.

Tap the pan lightly to remove air bubbles.

Refrigerate for at least 4 hours, or preferably overnight, until fully set.

Once set, carefully remove the cheesecake from the pan.

Top with lemon zest and slices if desired, then slice into bars and serve chilled.