In a mixing bowl, combine the creamy peanut butter, unsalted butter, confectioners' sugar, fine sea salt, vanilla extract, and whole milk. Use a spatula or whisk to blend all the ingredients until smooth and creamy.
Cover the bowl with plastic wrap or a lid. Place it in the refrigerator for about 30 minutes.
While the filling chills, prepare the chocolate. Use a double boiler or microwave to melt the semi-sweet chocolate, stirring until fully melted and smooth.
Once the peanut butter filling has chilled, scoop out a small amount and roll it into a small ball, then flatten it slightly into a heart shape.
Dip each peanut butter heart into the melted chocolate, ensuring it is fully coated. Place the coated heart onto a parchment-lined baking sheet.
Place the baking sheet in the refrigerator for about 20 minutes or until the chocolate hardens completely.
Once the chocolate has set, your Homemade Reeses Peanut Butter Hearts are ready to be enjoyed!