Melt the candy melts in a glass microwave-safe bowl for 30 seconds. Stir. Repeat microwaving and stirring another two times.
Using a small silicone bundt pan, coat the inside well with the melted orange candy melts. Give the silicone pan a tap on the counter to get out the bubbles. Make sure the edges are clean and there are no jagged edges.
Place in the fridge to set up for about 10 minutes.
Make sure there are no weak spots or super thin spots in the shell. If there are, place some more chocolate in the thin spot. It will set quickly since the mold will be chilled.
If the chocolate doesn't peel off easy, place it back in the fridge because it's not set completely. Leave it for aother 5 minutes.
Repeat making another 5 bundt pan shells. This will make a total of 3 pumpkins.
Place a mixture of the candy corn, M&M's and sprinkles into one side of the pumpkin. Repeat with two more.
Place the tops on each of the pumpkins.
Heat up the remaining orange candy melts that you didn't use up.
Place the candy melts into a sandwich bag.
Pipe the candy melts into any gaps and along the two seams. Run your clean finger along the seam to clean off any excess melt. Wipe off on a towl. Repeat with the two remaining pumpkins.
Knead 1-2 drops of chocolate brown gel paste into white fondant. Once completely kneaded, if you would like more color, add another 1 - 2 drops and knead until fully incorporated.
Roll the 3 pieces into an oblong shape. Cut 4 - 5 lines long ways down it. Give the nub a twist and place on the pumpkin. Repeat with two more.
Roll out super thin vines with the fondant. Wrap it around the stem and give it a curl.