In a large mixing bowl or stand mixer, cream together butter, brown sugar, 1 cup granulated sugar, and peanut butter.
Add eggs, flour, baking soda and vanilla extract and mix until combined.
Roll dough into 1 inch balls, roll in additional 1/2 cup sugar and place on ungreased cookie sheet. Use a fork to make a criss-cross design on top.
Bake for about 10-12 minutes or until golden brown.
Once removed from the oven, allow them to cool for 10 minutes. Move the cookies to a cooling rack or paper towel.
While the cookies are still warm, press the chocolate balls into the middle, just slightly pressing down.
Using the black gel, create 4 legs on each side and use small dots of gel to stick the candy eyes on.
Let the cookies cool completely.
Enjoy your spooky treat
Notes
You could also use melted milk chocolate chips to stick the eyeballs onto the chocolate ball. They will blend a little easier and they will harden quicker, but I am all about saving time, so I just used the gel.