Preheat oven to 180C. Line oven trays with baking paper.
Beat butter, sugar, egg and vanilla essence in a bowl with electric mixer until combined.
Slowly stir in sifted flour, baking powder and bi-carb. Add choc chips and coconut.
Drop tablespoons of mixture 5cm apart onto trays.
Bake cookies for approx. 12-15 minutes. Allow to cool on trays.
Use a bit of melted chocolate to glue on two maltesers per cookie to form the spider's body.
Using a piping bag, create four lines of melted chocolate on each side of cookie to form the spider's legs.
Stick on candy eyeballs with remaining melted chocolate.