In bowl, toss together broccoli, about 1 ½ tablespoons of olive oil, sugar, and 1 teaspoon of salt. Spread out on rimmed baking sheet. Toss potatoes in same bowl and drizzle with remaining ½ tablespoon of olive or and sprinkle with remaining ½ teaspoon salt. Mix them around in the bowl to help coat evenly.
Place potatoes on baking sheet alongside broccoli. Roast in oven for 20 minutes, turning with spatula once, or until broccoli turning lightly brown and crispy in some places. If potatoes don’t seem soft to the touch yet, remove broccoli from pan to cool and let potatoes cook an addition 5 to 10 minutes.
Turn oven down to 375 F degrees for use later.
After potatoes have cooled enough to handle, slice each in half crosswise. Using a teaspoon, scoop out most of the flesh from the center, keeping just a bit near the skin to create a “bowl.” Spray mini muffin tin with cooking spray and set each bowl in an opening (there should be 12).
Add scooped out flesh, ½ cup of cheese, ranch dressing, and pepper to bowl and mash together. Finely chop up roasted broccoli and stir into potato mixture. Using a spoon, stuff this mixture back into each potato half, mounting high. Sprinkle with remaining cheese and return to oven (turned down to 375 F degrees) for 10 to 15 minutes, or until cheese bubbling and tops turning lightly golden brown.
Drizzle with additional ranch dressing, if desired, and serve warm.