Preheat an oven to 180ºC.

Grease a springform tin and line with parchment paper.

Fit the K-Beater to the machine.

Add biscuit crumbs, sugar, butter and zest of 1 lime into the Mixer bowl.

Attach the Mixer bowl to the machine and fit the splashguard.

Start the machine on speed min and mix for about 4 minutes or until you reach a sand-like mixture.

Press the mixture into the base of the tin in an even layer.

Place into the preheated oven and bake for 10 minutes at 180°C.

Let cool and reduce the oven to 160°C.

Retrieve, clean the Mixer bowl and fit the Whisk Tool.

Add egg yolks to the bowl.

Start the machine on speed 2 and mix for 1 minute.

Add condensed milk, zest and juice of remaining limes to the bowl.

Mix on speed 1 and mix for 1 minute.

Pour the lime mixture on to the biscuit base.

Retrieve, clean the Mixer bowl and fit the Whisk Tool.

Add egg whites and tartar into the Mixer bowl.

Attach the Mixer Bowl to the machine.

Start the machine on speed 4 and mix for 3 minutes, keep the machine running.

Add caster sugar while the machine is running.

Mix on speed 4 and mix for 3 minutes or until stiff peaks form.

Spoon the meringue on to the lime mixture and spread to form a peak in the middle.

Bake for 20 minutes at 160°C until the meringue is golden and toasted in places.

Cool and chill in the fridge for at least 4 hours before serving.

 

Serve.