Bring a pot of salted water to a boil and cook the whole wheat penne according to package directions until al dente.
While the pasta cooks, slice the chicken breast into bite-sized pieces and season with sea salt, black pepper, and garlic powder.
Heat the olive oil in a large skillet over medium-high heat and sear the chicken until golden brown and cooked through, about 5-7 minutes.
Reduce the heat to low, add the minced garlic to the skillet, and sauté for 1 minute until fragrant.
Reserve 2 tablespoons of the hot pasta water, then drain the pasta.
In a small bowl, whisk together the Greek yogurt, parmesan cheese, and the reserved pasta water to create a smooth sauce base.
Add the cooked pasta and baby spinach to the skillet with the chicken, tossing until the spinach is just wilted.
Remove the skillet from the heat and stir in the creamy yogurt mixture until every noodle is well coated.
Garnish with fresh chopped parsley and serve immediately.