Mix together the flour, ¼ cup sugar, baking powder, cinnamon, vanilla extract, sour cream, milk, and eggs. Mix for 30 seconds until batter is creamy and no lumps are present.
Spray the slow cooker with non-stick cooking spray and pour the batter into the slow cooker, spreading the batter evenly on the bottom.
Wipe out the batter bowl. Then, gently mix together the 3 cups fresh blueberries, 1 cup sugar, lemon juice, and lemon zest.
Pour the blueberry mixture on top of the batter in the slow cooker. Place the lid on the slow cooker and cook on HIGH for 2-½ hours.
Once the cobbler is done, divide evenly among bowls and add a scoop of vanilla ice cream.