Preheat oven to 450ºF. Place an inverted rimmed baking sheet on a middle rack.Bring a large skillet to medium-high heat and add the butter. When the butter is melted, add the onions to the skillet along with a pinch of salt. Cook, stirring the onions occasionally for 10 minutes. Reduce the heat to medium and continue to cook for 10 more minutes, stirring occasionally until the onions are dark golden brown. Set aside when finished.Meanwhile, preheat your oven broiler. Put the halved jalapenos on a small baking sheet and broil on an upper rack for 10–15 minutes until the jalapenos are soft and begin to brown on the edges. Set aside and dice them up when they’re cooled off.Place a large piece of parchment (one that will fit on top of an inverted rimmed baking sheet with a little overhang) on the counter. Spread your dough out on the parchment in an oblong shape or a rectangle, if you like. Make sure the dough won’t be bigger than the back of that baking sheet.Spread the bbq sauce evenly over the pizza dough, leaving an inch or so around the border. Add the pulled pork, caramelized onions, and diced roasted jalapenos to the dough, distributing them evenly. Sprinkle on the cheese.Take out a second rimmed baking sheet and turn it upside down. Carefully slide the parchment with the pizza onto the inverted baking sheet. Then transfer it to the really hot inverted baking sheet in your oven. (If you only have one baking sheet, see note below.)Bake for 15–20 minutes until the crust is puffed up and turning light golden brown underneath and the cheese and toppings are heated through and the cheese is beginning to get brown spots as well.Remove from the oven and let it sit for 5 minutes or so before slicing and serving. Enjoy!Note: You’ll get a better cooked crust with a crispier bottom if you cook the pizza on a preheated surface. If you only have one rimmed baking sheet or think my crazy method is too complicated, just slide the parchment into a rimmed baking sheet (not inverted) and put it in the oven.