Combine water, piloncillo, canela, and cloves and bring to a boil. Lower heat to a simmer and cook, uncovered, stirring until piloncillo has dissolved, about 5 minutes. Cover, remove from heat, and let steep for 2 hours. Strain and discard solids.
Heat oven to 350°F. Arrange cubed bread on a baking sheet in a single layer and toast until golden, about 10 minutes.
Grease a 9 x 13-inch baking dish and set aside.
Combine bread, 3/4 of the cheese, pecans, pineapple, and 3/4 of the butter in a large bowl. Pour syrup over and stir until bread is well coated. Transfer to the baking dish and top with remaining cheese, and dot with remaining butter.
Grease a sheet of foil and cover the baking dish with the greased side down. Bake for 40 minutes, uncover and bake for 30-40 minutes more or until cheese is melted and golden on top. Serve warm with vanilla ice cream.