Adaptrix
Sour-cream topping
Skip the double crust. Make half the
crumb crust and press into the base.

For topping, combine 250 g (9 oz)
cold full-fat sour cream, 10 g (¼ oz)
caster (superfine) sugar and a teeny
bit of vanilla paste and gently hand
whisk together. Take the cheesecake
out of the oven, pour over the
sour-cream topping and carefully
and quickly smooth out. Return
to the oven for 10 minutes to set
the topping.

No-food-processor method
If you don’t have a food processor
to build the cheesecake batter, just
cream the cream cheese, sugar,
salt and vanilla. When smooth, add
the egg and crème fraîche. Toss the
banana with the lemon juice and
blitz with a blender, stick blender
or, as a last resort, push through
a coarse sieve (it’s hard work, but
do-able). Hand whisk the banana
puree into the creamed base mix.

The finger depth gauge works better than trying to see how far the water is
up the side of the dish, because water distorts depth perception.

Carefully lift the roasting tray into the oven. Bake for 60–70 minutes
until the cheesecake, when jiggled, barely wobbles. The internal
temperature will be 70°C (158°F) – it can be hard to tell with a top
crust, so internal temperature is the best way to achieve cheesecake
confidence.

With its crunchy top crust, I bake this cheesecake a bit further.

If the cheesecake is cooking too fast or far, the filling will puff and cause
the crumb to crack on top. If this happens, lower the heat and continue to
bake to doneness. The puffing will subside a little upon cooling.

The best thing about water-bath baking is that it is super hard to fully
overcook the cheesecake.

When ready, turn the oven off and leave the door ajar for 30 minutes
before removing the cheesecake. If you are using foil around the tin
and you can see some water has breached the foil, lift the cheesecake
tin out immediately and remove the foil so the base doesn’t become
sodden, then leave to cool to room temperature. Lightly cover with
plastic wrap and refrigerate overnight until set.

The next day, juice the limes and simmer to a syrup with the caster
sugar. Cut the tropical fruits into thin slices and lay on a plate. Cool
the lime syrup, then pour it over the fruit. Set aside.

Immerse the tin in a shallow roasting tray of hot water for 20 seconds
to warm the butter in the crust and loosen the cheesecake from the
tin. Place a flat plate or board (the base from a tart tin works well
here) on top of the cake in its tin. Flip over confidently and place the
plate on the work surface. Lift a side of the tin and gently tease out
the baking paper. This will loosen the cheesecake and, with a wiggle
and a shake and a push on the base, it should release. Peel the paper
off the crumb crust and re-invert.

If the cheesecake is stubborn and won’t come out, warm the tin further by
giving it a quick flash with a brûlée torch. Warming the butter in the base
will help it release.

Decorate the top with pretty and relaxedly strewn peeled slices of
tropical fruits. Serve chilled.

* Tonka beans have the most incredible almondy, marzipan flavour. It’s a
fermented seed of a South American tree. Some call it ‘spicy vanilla’, and
it’s redolent with magnolia, cherries and cloves. Caveat caker: it contains the
controversial chemical coumarin. I suggest a cup of tea and a good internet
read-up on its history and usage. For those about to bake, know that the
amount used here is not toxic, but if you are worried, just replace it with
vanilla bean or paste, or omit entirely.