Preheat oven to 375° F.
Cream butter,sugars and peanut butter with electric mixer in a large bowl. Once mixed beat in eggs, milk, corn syrup and vanilla. Add dry ingredients, flour, salt and baking soda. Mix on medium speed for three minutes or until combined.
Shape into 1-inch balls and put on ungreased cookie sheets, place 2 inches apart. Bake for 7 to 9 minutes or until lightly browned. Immediately press 1 chewy caramel in center of each cookie. Cool 2 minutes; remove from cookie sheets to cooling racks.
Cut licorice into 8 (2-inch) pieces for each spider. Attach legs by sticking into chewy caramel. Use M&M’s® minis chocolate candies for eyes and black gel to make pupils in eyes.