Preheat your oven to 350°F (175°C) and lightly grease the muffin tin with cooking spray or olive oil to prevent sticking.
In a sauté pan over medium heat, add the hot Italian sausage. Cook until browned, breaking it into small pieces as it cooks, about 5-7 minutes. Remove from heat and set aside.
In the same pan, add the finely chopped shallot and sauté for 2-3 minutes until translucent. Then add the chopped kale and cook until wilted, about 3-4 minutes. Season with salt and pepper.
In a large mixing bowl, whisk the scrambled eggs and season with salt and pepper. Add the cooked sausage and sautéed kale mixture, stirring to combine thoroughly.
Evenly distribute the egg mixture into the prepared muffin tin, filling each cup about three-quarters full.
Bake in the preheated oven for 20-25 minutes, or until the muffins are set and slightly golden on top.
Remove the muffins from the oven and let cool in the tin for a few minutes before transferring to a wire rack. Enjoy warm or store for later.