Preheat oven to 400°. Butter a loaf pan, then place a piece of parchment paper in the pan so that it covers the bottom and sides.
Place the pizza dough on a floured board. Roll the dough out into a large rectangle about ten by twenty inches.
Brush the melted butter over the dough. Sprinkle mozzarella and cheddar cheese over dough, then top with the jalapeños, distributing evenly.
Using a sharp knife, cut the dough lengthwise into three long strips. Cut each strip into six squares.
Working four or six at a time, stack the squares, being careful not to lose too much of the cheese.
Place the layers of squares vertically in the prepared pan.
Bake bread until puffed and golden brown, about twenty five minutes.
Let cool slightly before serving.
