Preheat oven to 400 degrees F (200 degrees C). Grease a 9-inch cake pan.
Mix corn flour, sugar, baking powder, baking soda, and salt together in a large bowl.
Mix almond milk, oil, and maple syrup together in a small bowl. Fold into the corn flour mixture until batter is just moist. Spread mixture into the prepared cake pan.
Bake in the preheated oven until a knife inserted into the center comes out clean, 20 to 25 minutes.