Add peanuts to a food processor and blend until a thick nut butter forms, 5-7 minutes. Stream in oil and vanilla with the processor on, continuing to run it until the mixture is smooth – this took me about 5 minutes. You can add more oil if needed, just do it in small increments. Turn off processor, add honey, and turn processor back on. Blend until smooth.
Keep at room temperature for a week, or if keeping longer, refrigerate in a sealable container.