Line a 8x4 inch loaf pan with parchment paper.
In a medium bowl, mix together the peanut butter, coconut oil, maple syrup and vanilla until smooth. Pour the fudge into the pan and tap the pan on the counter before putting in the freezer. Freeze for 10 minutes, then sprinkle chopped peanut butter cups on top of the fudge and press them in a bit if necessary. Sprinkle with a little Maldon sea salt. Freeze until firm, about 30 minutes-1 hour.
Once fudge is firm you can cut into 15 squares. Sometimes you have to wait a few minutes before cutting into. Store fudge in a freezer safe container in the freezer for up to 3 months.
