Position a rack in the upper third of the oven and preheat the oven to 350°F. Lightly oil the cups of a muffin pan or line it with paper liners.
Combine the almond or soy milk with the apple cider vinegar and let stand for about 5 minutes. It will develop a buttermilk-like consistency. Whisk in the apple sauce and maple syrup.
Whisk together the cornmeal, whole wheat flour, baking powder, baking soda, and salt. Make a small well in the center and pour in the wet mixture. Mix well.
Fold in the corn, scallions and minced jalapeños.
Divide the batter among the muffin cups, filling them ¾ of the way full. Top each on with a jalapeño slice.
Bake until the muffins are golden brown around the edges and toothpick inserted in the center comes out clean, about 17 to 20 minutes.
Place the muffin tin on a wire rack and allow the muffins to cool for 10 minutes before carefully removing them.