Whip cold liquid cream in a bowl until medium-stiff peaks form — it should hold shape but still be soft enough to fold in other ingredients. Don’t over-whip or under-whip; we want it light and airy for the best texture.
Add condensed milk, mango pulp, and vanilla extract (if using). Whip again on high speed for 2–4 minutes until thick and fully combined.
If using a dish, line it with parchment paper and leave extra hanging over the sides for easy removal once set.
Arrange biscuits in a single layer on the bottom, smooth side down. Pour in the mango ice cream and spread it out evenly with an offset spatula.
Drop a few spoonfuls of mango pulp on top and swirl through for added flavor. Smooth the surface and top with another biscuit layer, this time with the patterned side up.
Freeze for at least 6–8 hours or overnight until completely set. Lift the slab out using the parchment, slice along the biscuit lines, and enjoy!