Bring a large pot of salted water to a boil over high heat. Carefully add the lasagna noodles and cook according to package instructions until al dente, around 8-10 minutes. Drain and toss with olive oil.

In a medium saucepan, melt 4 tablespoons of unsalted butter over medium heat. Whisk in 4 tablespoons of all-purpose flour for about 2 minutes. Gradually pour in 3 cups of whole milk, whisking until thickened, about 5-7 minutes. Season with salt and black pepper, then fold in ½ cup of basil pesto.

In a large mixing bowl, combine 15 oz of ricotta cheese, 1 cup of grated Parmesan cheese, and a large egg. Sprinkle in 1 tsp of dried basil, ½ tsp of garlic powder, and add salt and pepper to taste. Mix thoroughly.

Preheat your oven to 375°F (190°C). In a 9x9-inch baking dish, spread a layer of béchamel on the bottom. Layer noodles, the cheese mixture, shredded mozzarella, and basil pesto until finishing with noodles and a topping of béchamel and mozzarella.

Cover with aluminum foil and bake for about 50 minutes. Remove foil and bake an additional 10-15 minutes until top is bubbly and golden brown.