Heat the oven to 350 degrees. Have a 13-inch by 9-inch baking dish ready to use.
Rinse and drain the blueberries.
Put blueberries in a large skillet along with the 1 and 1/4 cup sugar. Mix in the cinnamon.
Bring to a boil over medium heat, then pour the berry mixture into the baking dish.
In a large mixing bowl, combine the flour, sugar, baking powder, and salt. Mix together.
Add the oil and milk. Mix to make a soft dough.
Place the dough on a breadboard and shape it into a rectangle roughly the size of your rectangular pan.
Slice the dough lengthwise into strips. Gather each strip and gently lay it on top of the berry mixture. It’s okay if there are gaps or tears.
Put the baking dish in the oven, uncovered, and bake for 20 minutes. The berries will be bubbling and the crust should be a little bit brown and raised.
Serve warm with vanilla ice cream.