Combine the arborio rice and vegetable broth in a medium saucepan. Bring to a simmer and cook, stirring often, until the rice absorbs most of the liquid and becomes tender, about 18 minutes.

Stir in the pumpkin puree, 1/2 cup of the mozzarella, the parmesan, and salt. Cook for 2 more minutes until the cheese melts and the mixture thickens. Spread the risotto on a baking sheet and let it cool completely.

Once cooled, mix in the remaining 1/2 cup mozzarella. Scoop about 2 tablespoons of the mixture and roll into balls. Place the balls on a plate.

Beat the eggs in one bowl and place the breadcrumbs in a second bowl. Dip each ball into the egg, then roll in breadcrumbs to coat evenly.

Heat 2 inches of vegetable oil in a large skillet over medium heat until it reaches 350°F. Fry the arancini in batches for 3 to 4 minutes per side until golden brown. Drain on paper towels.

Warm the marinara sauce and serve it alongside the hot arancini for dipping.