Cook the pasta according to package directions, reserve 1 cup of cooking liquid when draining the cooked pasta. Set aside pasta and pasta water.
Preheat the oven to 425 degrees.
In a large bowl toss the cubed eggplant with 2 tbsp of olive oil, ¼ tsp salt, ¼ tsp garlic powder and toss with your hands to combine well.
Transfer the eggplant to two large rimmed baking sheets lined with parchment paper.
Place in the oven for about 25-30 minutes or until the eggplant is fork tender and browned in spots, flipping halfway through.
While the eggplant cooks, heat a large skillet with tall sides over medium heat and add 2 tbsp of olive oil along with 10 oz cherry tomatoes. Cook the tomatoes for about 5-6 minutes on medium heat, using the spatula to smash some of the tomatoes so they are saucy.
Add the harissa, feta, pasta, ½ cup pasta water and stir well to combine and allow the feta to melt.
Next Add the spinach in batches, allowing it to wilt into the pasta after each addition.
Add the eggplant and fresh herbs to the pot and mix gently or serve the eggplant plated on top of the penne.
