Heat the oven to 375°F. Mince the garlic.

Wilt the spinach in a dry skillet over medium heat, about 2 minutes. Transfer to a clean towel, let it cool slightly, and squeeze out as much liquid as possible. Chop it finely.

In a bowl, mix the softened cream cheese, spinach, minced garlic, mozzarella, parmesan, and a pinch of the salt until evenly combined.

Lay each chicken breast flat and cut a deep pocket into the thick side, leaving about half an inch uncut around the edges. Spoon the filling into each pocket and close with toothpicks if needed.

Mix the remaining salt, black pepper, smoked paprika, and garlic powder and rub it over the outside of the chicken.

Heat the olive oil and butter in an oven-safe skillet over medium-high heat. Sear the chicken 3 minutes per side until golden.

Move the skillet to the oven and bake 18 to 22 minutes, until the thickest part of the chicken reads 160°F. Rest 5 minutes, remove the toothpicks, and serve.