Preheat the oven to 350 degrees F.
For the Bread - Cut the French bread in half widthwise. Then cut the halved piece of French bread in half lengthwise.
Select one of the quartered pieces of bread that has the rounded side. Cut a very thin slice off of the rounded side (the uncut side). If needed, cut off more thin pieces so that the bread will sit level when it's facing cut-side up with the rounded side on the bottom.
For the Toppings - On the cut side of the quartered piece of bread, spread softened butter. Also spread the butter on the cut-end of the bread.
Sprinkle granulated garlic on top of the bread. It's okay if the garlic isn't spread evenly on top of the bread at this point. Sprinkle chili powder on top of the bread.
Using a soft spatula, spread the granulated garlic and chili powder evenly into the butter on top of the bread.
Make 3 partial widthwise cuts about 3/4's of the way into the bread (so there are 4 pieces of bread). The bottom part of the bread under each cut should still be attached.
Top the bread with shredded cheddar cheese. Also add the shredded cheese in between the partially cut sections of bread.
On top of the cheddar cheese, add shredded Monterey jack cheese. Transfer the bread to an ungreased small cookie sheet, brownie pan or pizza pan.
Top with sliced nacho jalapeno peppers. Try to lay the jalapenos as flat as possible so that they don't slide off of the cheesy bread when baking.
Heating the Garlic Bread - Bake in a preheated oven until the cheese melts and the outside edges of the bread are crispy (about 13 minutes).
After heating the bread, if any jalapenos slide off to one side, add more to the top of the bread if needed.
Serve right away while warm as a side dish or appetizer.