Preheat oven to 400℉/200℃.
Mix the chia seeds with the milk in a small bowl and set aside to gel. It should take 15 minutes or so to attain the right consistency. Lightly oil a 8x8 glass baking dish.
In a large bowl, sift the cornmeal, corn flour, nutritional yeast, baking powder, baking soda, and salt together.
In a separate bowl, whisk the vinegar, coconut oil, maple syrup and squash puree until combined. Add chia and milk mixture, stir completely. Add the wet mixture to the dry, and combine in as few strokes as possible. Fold in the corn kernels and jalapeno.
Add batter to the prepared dish, smooth out the top. Bake until deeply golden, 40-45 mins. Let cool for at least 30 minutes in the pan. Cut into squares.