Melt the dark chocolate chips with coconut oil in the microwave in 20-second bursts, stirring until smooth.
Lay all the chocolate cookies flat on the parchment sheet. Spoon a small dab of melted chocolate onto the centre of each one.
Press a cone-shaped candy upright onto each dab of chocolate, holding it steady for 10 seconds so it bonds.
Pipe a thin ring of orange gel icing around the base of each cone where it meets the cookie brim to form the hat band.
Add a small square of yellow gel icing on top of the orange band for the buckle.
Scatter a pinch of edible glitter or sprinkles over the hat while the gel is still tacky.
Leave to set for 15 minutes before arranging upright on the serving platter.