Mix coconut cream, ginger, garlic, paprika, turmeric, cumin, ginger, garlic, and salt in a small bowl. Set aside.
Wash eggplants and cut into quarters lengthwise, but not going all the way to the stem; stop about 1/2 inch from the stem.
Gently open each eggplant and spoon the marinade into the crevices, making sure you coat the flesh completely.
Allow the marinated eggplant to marinate for at least 20 minutes. Meanwhile, prepare the sauce.
Heat oil in a large skillet over medium-high. Add onion and cook until soft, about 2 minutes.
Add garlic and ginger and cook, stirring for a minute.
Stir in cumin, coriander, cardamom, and turmeric, and cook until fragrant, stirring, about a minute.
Add tomato sauce, remaining coconut cream, water, and salt to taste. Bring it to a simmer.
Arrange marinated eggplants in the sauce, cover, and cook eggplants until soft and tender, about 20 minutes turning gently halfway.