Mix blueberries, 1/2 cup sugar, lemon juice, cornstarch, and vanilla extract. Set aside.
Whisk flour, 1/4 cup sugar, baking powder, and salt. Cut in butter until crumbly. Stir in milk and vanilla.
Grease Dutch oven. Pour blueberry mixture inside, then drop spoonfuls of the dough over it.
Campfire: Place Dutch oven over fire, cover, and bake for 30-35 minutes. Oven: Preheat to 375°F and bake for 30-35 minutes.
Brush with heavy cream, serve warm, and enjoy!