01 - In a medium bowl, beat together the peanut butter and softened butter until smooth and fully combined.
02 - Add the powdered sugar, vanilla extract, and salt. Mix until a soft, pliable dough forms that holds together easily.
03 - Line a baking sheet with parchment paper and set aside for the shaped 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 to the touch, which will make dipping easier.
06 - Melt the chocolate and coconut oil (if using) in a heatproof bowl over barely simmering water, stirring frequently until smooth and glossy. Alternatively, melt in short bursts in the microwave, stirring between each interval.
07 - Using a fork, dip each chilled heart into the melted chocolate to coat completely. Gently tap the fork against the bowl edge to let excess chocolate drip off, then place the hearts back on the parchment-lined sheet.
08 - Refrigerate until the chocolate sets completely, about 15 minutes. Store in an airtight container in the refrigerator for up to 1 week.