Preheat your oven to 375°F (190°C).
In a medium bowl, mash the chickpeas with a fork or potato masher until mostly smooth, leaving some chunks for texture.
Stir in the mayonnaise, Dijon mustard, lemon juice, celery, red onion, dill pickles, garlic powder, salt, and pepper until well combined.
Place the slices of bread on a baking sheet. Spoon the chickpea mixture evenly onto each slice.
Top each chickpea salad with shredded cheddar cheese.
Bake in the preheated oven for about 10-12 minutes, or until the cheese is melted and bubbly.
Remove from the oven and let cool for a minute before serving.