Preheat the grill or grill pan over medium-high heat.
Wash and dry the zucchinis. Cut off both ends and slice them into ¼ inch thick rounds.
In a bowl, combine the olive oil, garlic powder, salt, and black pepper. Mix well.
Brush the zucchini slices with the seasoned olive oil mixture on both sides.
Place the zucchini slices onto the grill or grill pan in a single layer. Grill for about 4-5 minutes on one side, until grill marks appear.
Flip the slices using tongs and grill for an additional 4-5 minutes on the other side, until tender and lightly charred.
Remove from the grill and transfer to a serving platter. Drizzle with balsamic vinegar if desired.
Serve warm as a side dish.
For added flavor, sprinkle with fresh herbs like parsley or basil after grilling.
You can experiment with different spices such as Italian seasoning or paprika for a unique twist.
Zucchini can also be served cold as a salad topping or appetizer.