Lightly spray a microwave-safe rectangular dish with cooking spray. In a bowl, whisk together the almond flour, coconut flour, eggs, baking powder, 2 tablespoons of softened butter, almond milk, salt, and Italian seasoning until smooth. Pour this batter into your prepared dish.
Microwave the batter for 2 minutes. While it's cooking, place a skillet on medium heat to preheat. Once done, carefully remove the bread from the dish and slice it into two pieces – your keto bread is ready!
Lightly butter one side of each bread slice with the remaining 1 tablespoon of softened butter. Place one slice, butter-side down, onto the preheated skillet.
Layer the 3 slices of cheese onto the bread in the skillet. Top with the second slice of bread, butter-side up.
Cook for about 1 minute per side, or until the bread is golden brown and the cheese is beautifully melted. Flip carefully halfway through. Enjoy your quick and cheesy creation!