Spray the inside of a 6-quart slow cooker very well with nonstick cooking spray.
In a medium mixing bowl, combine the flour, ¼ cup of the sugar, baking powder and cinnamon. Mix well.
Push the flour mixture to one side and add the egg and whisk it.
Mix in milk, vanilla and canola oil. Mix thoroughly until the mixture is fully combined. Pour into the slow cooker and gently spread evenly on bottom of the crock.
In a large mixing bowl, toss blueberries in the remaining ¾ cup of the sugar.
Pour blueberries and sugar into the slow cooker on top of the batter (don't stir) and cook on high for 2 - 2 ½ hours (check for doneness at 1 ¾ hours into cook time to see if you need the full 2 ½ hours.). The blueberries should be soft and the crust golden. Watch that the crust doesn't burn.
When cobbler is done cooking, turn off the slow cooker. Let the cobbler cool down a little.
Serve directly from the slow cooker. Be sure to scoop from the bottom as to get some of the cobbler crust with your blueberry mixture.
Serve with vanilla ice cream or whipped cream.