Rainforest Crunch Shake
A thick coffee milkshake with buttery cashew and Brazil nut brittle broken through it and crunched over the top. It is named after a nut buttercrunch that was a famous ice cream flavour in the 1990s, and this version is made from scratch.
At a glance
- Ice cream : liquid
- 3:1
- Active time
- 15 min
- Total time
- 55 min
- Makes
- 2 tall glasses
- Serve
- Cold, thick
- Kit
- Blender + pan
Ingredients
Note: The brittle makes more than you need. It keeps two weeks in an airtight tin.
Method
-
Toast the nuts
Toast the chopped cashews and Brazil nuts in a dry pan for three or four minutes until golden. Tip them out.
3 to 4 minutes -
Make the buttercrunch
Melt the sugar in a heavy pan over medium heat without stirring, swirling, until it turns a deep amber. Take it off the heat, stir in the butter and salt, then the nuts, and spread it quickly on baking paper.
6 to 8 minutes -
Cool and break
Leave it to set for thirty minutes, then break it into shards. Crush a third of it into small pieces.
Cool 30 minutes -
Blend the shake
Blend the softened coffee ice cream, cold brew and milk for fifteen to twenty seconds until smooth. Add two tablespoons of the crushed brittle and pulse twice.
Blend 15 to 20 seconds -
Pour and crunch
Pour into two chilled glasses, top with whipped cream if you like, and push shards of brittle into the top.
Why this works
Rainforest Crunch was a cashew and Brazil nut buttercrunch launched in the late 1980s by a company set up by Ben Cohen of Ben & Jerry's, with the stated aim of creating a market for nuts harvested from the Amazon. It became a Ben & Jerry's ice cream flavour and was well loved until it was discontinued around the end of the 1990s. This shake is a homage built from scratch rather than a copy of either product.
The brittle is a caramel. Sugar melted on its own breaks down and caramelises at around 170°C, developing the bitter-sweet, toasty flavours that read as toffee. Stirring in butter makes it a buttercrunch: richer, a little softer and less glassy than plain brittle. Salt sharpens it. It has to be spread quickly, because caramel sets fast as it cools.
Toasting the nuts first matters. Brazil nuts are rich and fatty with a mild, almost coconut flavour, and cashews are sweet and creamy. A few minutes in a dry pan drives the Maillard reaction on their surface and turns both deeper and nuttier, which stands up to the coffee.
The shake itself follows the coffee milkshake rules: mostly ice cream, very little liquid, short blending. The brittle goes in at the end and is only pulsed, so it stays in crunchy pieces instead of dissolving into sweet grit.
Variations
- With chocolate: drizzle melted dark chocolate over the set brittle before breaking it.
- With vanilla ice cream: add a teaspoon of instant espresso powder to the blender.
- Sundae: scoops of coffee ice cream with the brittle and a shot of hot espresso, no blender.
- Other nuts: macadamias and almonds make an equally good brittle.
Melted sugar reaches about 170°C and sticks to skin. Keep children away from the pan, do not taste it, and have a bowl of cold water nearby for any splashes. Contains nuts.
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Questions
What was Rainforest Crunch?
A cashew and Brazil nut buttercrunch launched in the late 1980s by a company set up by Ben Cohen, which became a popular Ben & Jerry's ice cream flavour before being discontinued around the end of the 1990s.
Can I use shop-bought brittle?
Yes. Any buttery nut brittle works. Crush some into the shake and break the rest on top.
Why did my brittle turn grainy?
The sugar was stirred while melting, which makes it crystallise. Swirl the pan instead of stirring until it is fully melted and amber.
How long does the brittle keep?
About two weeks in an airtight tin. Humidity makes it sticky.