• Preheat oven to 400.
• Lightly grease a 2-quart baking dish with cooking spray; set aside.
• Cook the macaroni according to the directions on the package.

In the meantime, prepare the sauce.

• In a small saucepan, whisk together milk, vegetable broth, flour, chili powder, salt, and pepper.
• Cook over medium-high heat for 4 to 5 minutes, or until sauce thickens.
• Remove from heat.
• Drain cooked pasta and return to pot.
• Add sauce to the pasta.
• Stir in 1 cup shredded mozzarella cheese; stir until melted and well combined.
• Layer 1/2-cup tomato sauce on the bottom of the previously prepared baking dish.
• Add half of the macaroni mixture over the tomato sauce.
• Top with half of the tomato slices; season with salt and pepper.
• Sprinkle 1-cup shredded mozzarella cheese.
• Dollop on the basil pesto.
• Top with the remaining pasta.
• Add the rest of the tomato slices; season with salt and pepper.
• Sprinkle with the remaining cheese.
• Bake for 22 to 25 minutes, or until bubbly and cheese is melted.
• Remove from oven.
• Let stand 15 minutes.
• Cut and serve.