Bring a large pot of water to a boil. Cook the lasagna noodles according to the package directions until they are al dente. Drain and toss with a splash of olive oil to prevent sticking. Set aside to cool slightly.

In the same pot, melt the unsalted butter over medium heat. Add flour, stirring constantly, for about 30-60 seconds to create a roux. Slowly whisk in whole milk, salt, and black pepper. Simmer gently, stirring until it thickens slightly, around 7-10 minutes. Remove from heat and stir in basil pesto.

In a medium bowl, combine ricotta cheese, freshly grated Parmesan, egg, dried basil, garlic powder, salt, and black pepper. Mix well.

Preheat your oven to 375°F (190°C). Spread 1/2 cup of the pesto béchamel sauce at the bottom of a baking dish. Cut cooked lasagna noodles in half and layer three strips at the bottom, overlapping slightly.

Dollop 1 cup of the ricotta cheese mixture over the noodles and spread evenly. Sprinkle with 1 cup of mozzarella cheese and 2 tablespoons of Parmesan.

Repeat the layering process until ingredients are used up. Finish with remaining noodles, pesto sauce, mozzarella, and Parmesan cheese.

Cover with aluminum foil and bake for 50 minutes, then uncover and bake for 10-15 minutes until golden brown. Allow to rest for 15 minutes before serving.