Line a 23cm springform cake tin with baking paper on the base and sides. Cut the side pieces so they extend at least 5cm above the rim of the tin to create a collar. This gives the ice cream mixture room to expand.

Break the biscuits into crumbs using your hands or pulse in a food processor until you have coarse crumbs. Do not grind too finely as you want some texture.

Mix the biscuit crumbs with the melted butter until well combined and the mixture resembles wet sand. Reserve 2 tablespoons of the crumb mixture for topping.

Press the remaining crumb mixture firmly into the base of the prepared tin, using the bottom of a glass to compact it evenly. Set aside.

In a large bowl, whip the cream using an electric mixer until soft peaks form. Do not overwhip.

Add the condensed milk, lemon zest and lemon juice to the whipped cream. Beat on medium speed until well combined and smooth. The mixture will thicken slightly as the lemon juice reacts with the cream.

Pour the lemon ice cream mixture over the biscuit base, smoothing the top with a spatula.

Sprinkle the reserved 2 tablespoons of biscuit crumbs over the top as garnish.

Cover the tin with plastic wrap and freeze for at least 4 hours, or preferably overnight, until completely solid.

Remove from the freezer 5-10 minutes before serving to allow it to soften slightly for easier slicing. Use a sharp knife dipped in hot water and wiped dry between cuts for clean slices.