01 - In a medium bowl, beat together the peanut butter and softened butter until completely smooth and creamy.
02 - Add the powdered sugar, vanilla extract, and salt. Mix until a soft, pliable dough forms that holds together well.
03 - Line a baking sheet with parchment paper and set aside for the cut hearts.
04 - Roll out the peanut butter mixture between two sheets of parchment to about 1/2 inch thickness. Using a small heart-shaped cookie cutter, cut out hearts and transfer them to the prepared sheet. Re-roll scraps as needed until all dough is used.
05 - Freeze the peanut butter hearts for 25 to 30 minutes until firm and completely set.
06 - Melt the chocolate and coconut oil (if using) in a heatproof bowl over barely simmering water as a double boiler, or microwave in short bursts, stirring until smooth and glossy.
07 - Using a fork, dip each chilled heart into the melted chocolate to coat completely. Let excess chocolate drip off, then place the hearts back on the parchment-lined sheet.
08 - Refrigerate until the chocolate sets, about 15 minutes. Store in an airtight container in the refrigerator for up to 1 week.