Bring a large pot of salted water to a boil. Cook the short pasta according to package instructions until al dente, about 8-10 minutes. Reserve ½ cup pasta water, then drain and set pasta aside.

Heat a skillet over medium-high heat, add olive oil and butter. Season chicken with salt, pepper, and garlic powder, then cook until golden brown and internal temperature reaches 165°F, about 5-6 minutes per side. Remove from skillet and set aside.

In the same skillet, reduce heat to medium, sprinkle in flour, and stir for 1 minute. Gradually pour in chicken broth and heavy cream, stirring until smooth. Add pesto, lemon juice, and chopped sun-dried tomatoes. Simmer for 3-5 minutes until sauce thickens.

Stir in spinach and cook for 2-3 minutes until wilted and bright.

Add drained pasta to the skillet, tossing gently with sauce. If sauce is too thick, add reserved pasta water gradually.

Slice the cooked chicken and arrange it over the pasta. Optionally, sprinkle with Parmesan cheese and serve immediately.