Spread Brussels sprouts evenly across two rimmed baking sheets, then massage with melted bacon drippings. Salt generously and roast for 10 minutes.
Add the asparagus tips to the pans with the Brussels, stir gently with a spatula, and cook for another 5 minutes. Remove pans from oven and turn heat up to 425 degrees.
While oven is heating, combine the cooked Brussels and asparagus onto a single pan. Add the pecans and cranberries, then drizzle with 1 1/2 Tbsp of the maple syrup, stirring with a spatula to coat all evenly. Add more salt if needed.
Wipe the second pan down and spread the bacon pieces evenly across it. Sprinkle generously with sea salt and cook for 12-14 minutes or until it reaches the color you like. (Note: If you're using thinner slices of bacon, cooking time will be much shorter!) Feel free to cook the bacon on the stove if you prefer.
Once bacon is cooked, strain the drippings and reserve for another use. Use a pastry brush to brush the remaining 1/2 Tbsp maple syrup across the cooked bacon pieces. Add more salt if needed, then stir the browned maple bacon to the mixture on the first pan. Toss all and serve immediately.
This is an incredible side dish, but I also love it as a one-dish main course - just increase the bacon to 1 pound, and add a sprinkle of Parmesan or feta to finish it off! Serves 8 as a side or 4 as a main.