Cut 8 slices of bread into circles using a cookie cutter, then set them aside.
Mix the mayonnaise, garlic powder, and Italian seasoning together in a small bowl.
Spread the mayonnaise mixture over one side of all 16 bread slices.
Spray a large skillet with nonstick cooking spray.
Place the 8 circle-cut pieces of bread in the skillet, mayonnaise-side down.
Cook the bread for 2 to 3 minutes, until browned, then remove the pieces from the skillet and set aside.
Place the remaining 8 slices of bread in the skillet, mayonnaise side down.
Place a slice of cheddar cheese on top of each piece of bread.
Place the browned bread pieces on top of the cheese, ensuring the browned side faces outward.
Insert a sliver of the orange bell pepper between the slices of bread to create a pumpkin stem.
Cook the sandwiches for 2 to 3 minutes until the bottom is browned and the cheese is melted.
Repeat until all the sandwiches are finished.
Create a spider out of black olives and place it on top of the warm sandwich so it slightly melts into the bread.
Serve the sandwiches warm alongside roasted tomato pepper soup.