Melt butter in a skillet over medium heat.
Add chopped kale and sauté for 2–3 minutes until wilted and tender, then remove and set aside.
In a bowl, whisk together eggs, salt, pepper, and garlic powder.
Pour the eggs into the skillet and cook gently, stirring occasionally, until soft and fluffy without overcooking.
Fold in the sautéed kale and candied bacon if using, then remove from heat.
Preheat oven to 350°F (175°C).
Slice croissants horizontally without cutting all the way through.
Fill each croissant with the egg mixture and top generously with shredded cheddar cheese.
Place sandwiches on a baking sheet and bake for 8–10 minutes until cheese is melted and croissants are lightly crisp.
Remove from oven, brush the tops lightly with honey or maple syrup, and sprinkle with Everything But The Bagel seasoning.