Preheat the oven to 400°F (200°C) and line or lightly oil a rimmed baking sheet.
In a mixing bowl, toss the cherry tomatoes and gnocchi with the olive oil, salt, and pepper until evenly coated.
Spread the gnocchi and tomatoes in a single even layer on the prepared baking sheet, leaving the bocconcini off for now.
Roast in the preheated oven for 15–20 minutes, until the gnocchi are plump and beginning to brown and the tomatoes start to burst.
Remove the pan from the oven and add the bocconcini balls; gently toss with a spatula to combine so the residual heat softens the cheese.
Scatter the chopped fresh basil over the sheet pan and drizzle with balsamic reduction if desired, then serve warm.
