Mix a small bit of each food coloring into a small bowl of baking soda. Use water to thin it out as needed. If you choose to add pumpkin pie spice do it now.

Press colored baking soda paste into cookie cutters.

Use a paper towel to soak up excess liquid off the top and clean around the edges.

Remove the cookie cutters.

Cut the end off of the cinnamon stick and break apart. Use to make a brown stem for your pumpkins.

Let your children play, encourage them to touch and smell before you make the pumpkins fizz. Then allow them to spray or dump vinegar onto the pumpkins. Encourage kids to squish and feel the fizzing pumpkins.