Step 1

Position rack in upper third of oven; preheat broiler to high. Bring a large pot of water to a boil.

Step 2

Combine ricotta, Parmesan and egg in a small bowl. Set next to the stove.

Step 3

Cook sausage in a large ovenproof skillet over medium-high heat, breaking up big pieces with the back of a spoon, until no longer pink, about 5 minutes. Stir in eggplant and oil; cook, stirring occasionally, until the eggplant starts to soften, about 2 minutes. Stir in marinara, fennel seeds and pepper. Reduce heat to maintain a simmer and cook, stirring occasionally, until the eggplant is very soft, about 7 minutes more.

Step 4

Meanwhile, cook pasta in the boiling water according to package directions. Drain and transfer to the pan with the sauce. Add the ricotta mixture and gently stir to combine. Bring to a simmer, then remove from heat. Evenly sprinkle mozzarella over the top.

Step 5

Transfer to the upper rack and broil until starting to brown on top, 1 to 2 minutes. Serve topped with basil, if desired.