Preheat oven to 375°F (190°C). Line a rimmed baking sheet with parchment paper.

On prepared pan, toss together blueberries and sugar; spread in a single layer.

Bake until juices have released and thickened, 35 to 40 minutes, stirring halfway through baking. Let cool completely on pan. Use immediately, or refrigerate in an airtight container for up to 1 day.