Add peanut butter and cookie crumbs to a medium bowl, and mix until blended.
Shape into 48 1-inch balls, and place the balls on a parchment-lined baking sheet.
Freeze for 10 minutes.
Dip balls in melted chocolate, and place in a single layer on a shallow waxed paper-lined pan.
If topping with chopped peanuts or sea salt, work quickly because the chocolate will set quickly.
Refrigerate for 1 hour, or until firm.
Notes
Peanut butter: I recommend using regular creamy peanut butter. No stir peanut butter can be too oily, which will give you loose filling.
Oreo cookies: I used regular Oreo cookies. Feel free to use any flavor of Oreo cookie that you think will go well with peanut butter, i.e. dark chocolate filled Oreo cookies.
Semisweet chocolate baking chocolate: I don't like to use chocolate chips because they can have ingredients that make it difficult for them to melt properly. Dark chocolate melting wafers or chocolate almond bark will also work.