I used blanched almonds but you can use whole almonds.

Both the almonds and cashew nuts should be unsalted.

Preheat the oven to 175 °C/ 350 °F.

Spread the almonds and cashews over a baking sheet and place in the oven for 12-15 minutes.

Keep an eye on the nuts.

If they get burnt, they will have an unpleasant bitter taste.

When done, remove from the oven and set aside to cool down.

Place the nuts into a food processor and using a grating blade pulse until smooth - this may take some time, so be patient.

You can reserve some chopped nuts for later to create a chunky texture.

Update: Since I got my new Kenwood mixer with a food processor attachment, I don't use anything else to make nut / seed butter.

It's strong, doesn't overheat and takes just a few minutes to make smooth butter! At first, the mixture will be dry.

Scrape down the sides of your processor several times with a rubber spatula if the mixture gets stuck on it.

Add the oil and ...

...

keep blending until you reach the desired consistency.

This could take 5-15 minutes depending on which food processor you are using.

You don't need to use the oil but I prefer to add some to create a smoother texture.

I used an immersion blender from Bamix but you may find it easier if you use Vitamix or Blendtec.

Spoon the butter in a glass container and keep refrigerated or at room temperature.

Enjoy!