Spread the cashews out into a single layer on a baking sheet and toast for 12 minutes, until fragrant. Set them aside to cool.
If your almond bark is in a single chunk, cut it into pieces and add to a microwave safe bowl. Mine came already partitioned into chunks which was handy.
Microwave for 90 seconds, and stir. Microwave in further 15 second increments, stirring in between, until the bark has melted and become smooth and creamy. Don't over heat it, I like to let it rest in between bursts of microwaving to allow the heat of the bowl to assist in melting. My bark took another 45 seconds, but yours might take more or less time. Note: if using white chocolate you will need to melt it carefully in a double boiler.
Stir the cashews into the melted bark.
Drop by rounded tablespoons onto parchment paper. You can adjust the shape of your clusters as you drop them. There's no need to rush, the bark will remain nice and molten for a while.
Let the bark set up before moving the clusters. You can store them at room temperature, or in the refrigerator.
I made my clusters quite large, but you can make yours smaller if you prefer.
add a touch of sea salt to the mixture, or on top, if you like.