Make the nut butter base: Place the cashews, macadamia nuts, salt and vanilla in the bowl of a food processor and process until smooth and creamy. You may need to stop the motor and scrape the sides of the bowl a few times, but the butter should come together rather quickly due to the high fat content of the macadamia nuts.
While the nut butter is processing, make the white chocolate: Put the finely chopped cacao butter in a small microwave-safe bowl and heat on high in 30-second to 1-minute intervals, mixing well between intervals, until completely melted, 2 to 3 minutes total.
In a separate microwave-safe bowl, mix together the coconut butter and honey and melt on high, which shouldn't take more than 30 seconds to 1 minute. Add the melted cacao butter to the coconut butter mixture one-third at a time, whisking each addition until well combined.
Add the white chocolate to the nut butter by pouring it down the feeding tube while the food processor is running. Continue processing until well incorporated.
Stop the motor, add the add-ins, and pulse a few times just to mix the in, no more.
Transfer to an airtight glass container and allow to rest for at least 24 hours before eating. Store in a cool, dark, dry place, where it will keep for up to a few months.
*In step 2 and 3 above, instead of using a microwave, I melted the ingredients in a double boiler. For this you need a small saucepan with a just enough water to cover the bottom of the pan. Heat the water on low heat and place a heat-proof glass bowl on top. Add your ingredients to the bowl and allow them to melt slowly. *Be sure to stir the content in the jar of coconut butter well before measuring so that you don't just use the oils that rise to the top.Nutritions facts (per tablespoon): Calories: 120 • Total fat: 11.4g • Total carbs: 4.8g • Net carbs: 3.7g • Protein 1.6 g