Start by greasing your slow cooker with a little butter or cooking spray.
In a large mixing bowl, combine the white whole-wheat flour, yellow cornmeal, coconut sugar, kosher salt, baking powder, and chili powder. Whisk them together until evenly blended.
In a separate bowl, whisk together the egg, Greek yogurt, skim milk, and melted butter until smooth.
Gradually pour the wet mixture into the dry ingredients, stirring gently until just combined. Be careful not to overmix.
Gently fold in the sliced jalapeƱos, distributing them evenly throughout the batter.
Transfer the batter into the greased slow cooker, spreading it out evenly.
Cover the slow cooker and set it to low for about 3 to 4 hours.
Once cooked, let the cornbread cool for about 10 minutes before slicing and serving.