Heat oven to 425. Place bread (I used regular ol' white bread - adjust cook times to thickness of bread you choose.) on cookie sheet and place in oven for 5 minutes until slightly toasted. Melt butter in bowl, add mayo, stir, then garlic powder, and cheese. You should have a cheesy paste. Spread onto slices of bread, return to oven for 4-5 minutes, or until cheese is melted. Finish under broiler for a slightly crisp appearance. NOTE: These are "guesstimates" of measurements, I mostly just threw the things together.