Preheat oven to 180˚C.
If raw peanuts, roast for 15 - 20 mins. (note: the longer you roast, the richer the nut butter but keep in mind if you overcook the nuts, it will have a bitter and burnt taste).
Let cool. If using skinless peanuts, skip to step 3. Otherwise, remove skin by placing peanuts in a tea towel and rub vigorously to loosen. Then separate peanuts from skin by using a colander or a draining spoon.
Transfer skinless peanuts to a blender and blend until you reach the right consistency. This can take a while so be patient. It may seem ready but don't be tricked, keep blending until it is quite runny. Optional, add sea salt and blend to mix through.
1 cup of peanuts will yield 1/2 cup nut butter