Preheat oven to 350℉ (180℃). Line a regular muffin tin with cupcake liners or oil the muffin tins to prevent sticking.
In a medium mixing bowl, add the egg, coconut oil, applesauce and yogurt. Beat together using a hand-held mixer or whisk.
In a large mixing bowl, using a wire whisk, blend together the flour and baking soda.
Add the wet ingredients to the dry ingredients and mix together with a hand-held mixer or large spatula/spoon. Mix just until batter forms - it will be thick.
Add the minced kale and incorporate it into the batter.
Spoon the pupcake batter into the muffin cups, about 3/4 the way full.
Place in the preheated oven and bake for 20 minutes or until a toothpick inserted in the middle comes out clean.
Cool cupcakes to room temperature on a wire rack while you make the frosting.