Cook the sweet potatoes in sugar and spices: Using the same skillet you used to toast the pepitas, keep the heat at medium and add 2 teaspoons oil. Once the oil starts to shimmer, add the cubed potatoes. Stir to coat. Cook for about 1 minute. Stir again. Add the water. Cover and leave untouched for 5 minutes.
Combine sugar, paprika, cayenne, and salt in a small bowl. Add the spice mixture to the potatoes. Stir to coat.
Cook uncovered for 7 additional minutes. Don’t stir. The sugar should be caramelized, one side of the potatoes should be brown, and the potatoes should be tender but still hold together.
Remove the potatoes from the skillet and place them on the plate alongside the pepitas. Tent with foil to keep them warm.
Serve the bowls: To the bowls with the black beans, add a 1/2 cup of sweet potatoes, 1/2 cup quinoa, and the spinach. Top with toasted pepitas, crumbled cotija, a squeeze of lime, and a drizzle of creamy lime hot sauce.
