Bring a pot of salted water to a boil and cook the pasta according to package instructions; drain and set aside.
Heat 2 tablespoons butter in a 12-inch skillet over medium heat.
Add the cubed chicken and cook, stirring occasionally, until browned and cooked through, about 8 minutes; transfer the chicken to a bowl and set aside.
Prepare the roasted red pepper cream sauce in the same skillet according to the sauce recipe instructions.
Add the drained pasta to the skillet and toss with the cream sauce using tongs until evenly coated.
Return the cooked chicken to the skillet, add the fresh spinach, and remove the pan from the heat.
Toss everything together until the spinach wilts; season with salt and pepper to taste.
Serve warm.