Begin by combining powdered sugar, melted butter, salt, and peanut butter in the bowl of a stand mixer.
1 ½ cups powdered sugar, ⅛ cup butter, ¾ cup peanut butter, 1 pinch kosher salt
Mix it all together but do not be alarmed - it will look like a dry crumbly mess.
Then, mix in the milk. You want the dough to stick together and be like a dry cookie dough. You don't want this to be sticky like chocolate chip cookie dough.
1 tablespoon milk
Now, sprinkle some powdered sugar on a clean surface for rolling out the dough. (I recommend using powdered sugar over flour because these are not being cooked - raw flour is not meant to be consumed.)
Roll the dough out using a rolling pin (you might need to sprinkle sugar on the rolling pin as well) until it is the thickness that you want for your treats. (I like to do some about ¼ inch thick for me - equal amounts of chocolate and peanut butter - and ½ inch thick for my husband - extra peanut butter.) I like to use a cold marble rolling pin for this - it seems to help keep the dough cold which makes it easier to work with. Once the dough is rolled out, use your favorite cookie cutters to cut out different shapes.
Either lay them on parchment on a cookie sheet that fits in your freezer or use my favorite method - fold a piece of parchment over in layers in a freezer-safe container. (It is much easier to fit a small container in the freezer than a cookie sheet.) (There is a picture of this above for reference.)
When you are about to take the peanut butter pumpkins (or ghosts, eggs, etc.) out of the freezer, start melting your chocolate. I like to use a double boiler as I find that this melts the chocolate more quickly, smoothly, and evenly. (This means to bring a pot of water to a boil and place a heat-safe bowl on top of it.) Place the chocolate chips and coconut oil in the bowl and stir until the chocolate chips are melted. I like to use a rubber spatula to do this so I can scrape the sides of the bowl really well.
1 bag milk chocolate chips, 1 tablespoon coconut oil
Once the chocolate is fully melted, remove the peanut butter shapes from the freezer and dip them in the melted chocolate. They will quickly soften, so do not leave them in the chocolate for too long.
Transfer them to wax paper to cool. (Do not place them directly on a baking rack - they will get stuck and break as you try to remove them - speaking from experience.) If you miss any spots, you can drizzle chocolate over the candies with a spoon.
sprinkles/chopped nuts, candy eyes
Once all your chocolates are coated, put them in the refrigerator for the chocolate to set. 30 minutes to an hour should be enough, but you can wait longer if you want to be sure they are really set. (If you are adding eyes, sprinkles, or chopped nuts, add them before refrigerating - while the chocolate is still soft. You can drizzle caramel on after they are cool.)
caramel
Once the chocolate sets, transfer your candies to an airtight container and store them in the fridge or eat them immediately!