Preheat oven to 350 degrees F (175 degrees C). Place a greased, 10-inch cast iron skillet in the preheating oven.
Mix soy milk and vinegar together in a bowl. Let stand until curdled, about 5 minutes.
Mix cornmeal, flour, baking powder, and salt together in a bowl.
Pour oil and maple syrup into the soy milk mixture. Whisk with a fork until foamy, about 3 minutes. Pour over cornmeal mixture and mix until combined. Fold in corn kernels. Pour batter into the hot skillet.
Bake in the preheated oven until a toothpick inserted into the center comes out clean, 25 to 35 minutes. Slice into squares or wedges.