Heat the vegetable oil in a large pot over medium heat.
Add the minced garlic and grated ginger and sauté for 1 minute until fragrant.
Pour in the chicken broth and water, then bring to a simmer.
Add the sliced shiitake mushrooms and julienned carrot to the pot and simmer for 5 minutes.
Stir in the soy sauce and miso paste until the miso paste is fully dissolved.
Add the ramen noodles to the pot and cook for 3 minutes, stirring occasionally to separate the noodles.
Slowly stir in the heavy cream and continue to simmer for another 2 minutes until the broth is creamy and noodles are tender.
Create a small well in the center of the pot and crack in the egg. Cover the pot with a lid and cook for 2-3 minutes until the egg white is set but the yolk remains runny.
Remove the lid and gently stir in the baby spinach leaves until wilted.
Season the ramen with toasted sesame oil and black pepper, then sprinkle sliced green onions on top.
Serve immediately, ladling the creamy ramen and egg into bowls.