Preheat the oven to 450F. Line a large baking tray with parchment paper.
Add the potatoes to a large stockpot and cover with water. Turn the heat on high. Once the water is boiling, reduce the heat to medium-high, and simmer/boil gently for 15 to 20 minutes, or until fork-tender (the boiling time will depend on the size of your potatoes, so keep watch).
Drain the potatoes in a colander and let cool/dry for a few minutes.
While the potatoes cool, whisk together the brown sugar, chili powder, paprika, cumin, garlic powder, and smoke salt in a small mixing bowl.
Transfer the slightly cooled potatoes to a large mixing bowl, drizzle the oil over top and toss to coat. Sprinkle the spice mixture over top and toss to coat again.
Transfer the potatoes to the prepared baking tray, reserving any extra oil/spice mixture in the bowl.
Use the base of a metal measuring cup to smash each potato by pressing down until nearly flattened. It's ok if the potatoes break apart a bit.
Rub a bit of the reserved oil/spice mixture on each potato.
Roast the potatoes for 20 to 23 minutes, or until golden-brown and crispy on the bottom.
Serve the potatoes with a sprinkle of cilantro and a drizzle of bbq sauce, if desired.