Preheat oven to 350F/175Spread pistachios out over the baking sheet and toast for 6-8 minutes until fragrant. I like to keep an eye on them to make sure they do not burn and stir around 4 minutes.
Let nuts cool down until warm and add to food processor or high-speed blender. Process/blend until creamy while scraping down the sides every few minutes or so. This takes me around 10 minutes but it can take up to 15.
Do not add the optional flavors until creamy.
Let the butter cool down and then transfer to a mason jar.