01 - In a large mixing bowl, beat together the creamy peanut butter, softened butter, vanilla extract, and fine sea salt using a hand mixer or stand mixer until smooth and creamy.
02 - Gradually add the powdered sugar to the peanut butter mixture, mixing on low speed until a thick, pliable dough forms that holds its shape when rolled.
03 - Scoop out heaping teaspoonfuls of the peanut butter dough and roll between your palms into smooth 1-inch balls. Arrange them on a parchment-lined baking sheet, spacing about 1 inch apart.
04 - Place the baking sheet in the refrigerator and chill the peanut butter balls for at least 30 minutes, or until they are firm enough to handle without losing their shape during dipping.
05 - In a microwave-safe bowl, combine the chocolate chips with coconut oil or vegetable shortening. Microwave in 30-second increments, stirring thoroughly between each interval, until the chocolate is completely melted and smooth.
06 - Insert a toothpick into the center of each chilled peanut butter ball. Dip into the melted chocolate, leaving the top quarter uncovered to create the signature buckeye look. Gently tap off any excess chocolate.
07 - Return each dipped cookie to the parchment-lined baking sheet. Carefully remove the toothpick and use your finger to smooth over any visible holes or imperfections in the top surface.
08 - Refrigerate the dipped cookies for about 20 minutes, or until the chocolate coating is fully set and firm to the touch.
09 - Serve the buckeye cookies chilled or allow them to sit at room temperature for 10 to 15 minutes for a softer texture. Store any leftovers in an airtight container in the refrigerator for up to 2 weeks.