Combine all filling ingredients, except cilantro, if using, in a blender and blend until completely smooth.
Pour into a small saucepan. Constantly whisk over medium heat, until thick and bubbly.
Set aside to cool.
Meanwhile, slice each jalapeno lengthwise and remove all seeds and veins.
Preheat oven to 450 degrees.
Stir the chopped cilantro, if using, into the cheese sauce, then spoon the filling into each jalapeno half.
Place the non-dairy milk or water, flour, and bread crumbs in separate bowls.
Dip each stuffed jalapeno into the non-dairy milk or water, then the flour, then the non-dairy milk or water again, the finally into the bread crumbs to coat.
Place the coated jalapeno poppers on a silicone or parchment paper lined baking sheet.
Bake 15-20 minutes, or until browned.
Let sit 5-10 minutes before serving.