Preheat the oven to 350 degrees F. Spread the peanuts in a single layer on a sheet pan. Roast for 5-7 minutes until they are toasted and golden.

Transfer the peanuts to the bowl of a food processor. Pulse the nuts a few times to roughly chop them. Then process the peanuts for 4-5 minutes stopping to scrape the sides of the bowl as needed. The peanuts will go from finely ground to clumpy to smooth, thick peanut butter.

Store in an airtight container in the refrigerator for up to 2 weeks.