Place the marshmallow fluff and butter into a large saucepan over a low heat. Stir continuously until the butter is melted and the mixture is smooth.
Add in the orange food colouring, a few drops at a time until you get the desired shade of orange.
Add in the rice krispies and stir until all the rice krispies are orange.
Line a baking tray with grease proof paper/a silicone mat/Silpat.
I find the shaping easier wearing disposable gloves, but you can do it with bare hands if you'd rather. They don't stick at all to the gloves, so that's why I wore them!! - Take a heaping 2tbsp of mixture and shape into a ball.
Place onto your lined baking tray and stick either your large chocolate chips or curly wurly into the top of the pumpkin ball, in the centre.
Press a green M&M to one side of the stem. Repeat until you've used all the rice krispie mixture. This mixture makes 12-14 rice krispie treats.
Leave to set for 10 minutes before taking your black writing icing and drawing a face on one side of your pumpkin rice krispie treat. I did the simplest face possible with triangles for eyes and a zig zag for a mouth because I cannot draw, but go wild and get creative!
Leave to set for 10-15 minutes and then enjoy! Pumpkin Rice Krispie Treats will keep in an airtight container, at room temperature, for 5 days.