Set a large pot of salted water to boil. Cook spaghetti until al dente, about 2 minutes less than the package directions. Reserve 1 cup of pasta water before draining and set noodles aside.
Heat oil in a large skillet over medium-high heat. Add ground pork and press down without moving it for a few minutes to get a nice browned, slightly crispy base.
Stir in garlic, ginger, soy sauce, brown sugar, and spinach. Stir-fry quickly until fully combined and heated through. Remove from heat.
In a large mixing bowl, combine soy sauce, rice vinegar, peanut butter, chili crisp, brown sugar, and about half of the reserved pasta water. Mix until smooth.
Toss noodles in the sauce, adding more pasta water*** as needed. The sauce should coat the noodles evenly without being thick or gloopy
Place peanuts in a sealed ziplock bag and crush with a rolling pin until coarse. Alternatively, use a mortar and pestle or a food processor.
Divide dressed noodles evenly among serving bowls. Top each with a portion of the pork mixture, sliced green onions, and crushed peanuts. Serve immediately****.
*You can substitute 2 cups of fresh spinach for 1 cup frozen.
**Traditional Dan Dan Noodles use sesame paste, but I’ve swapped in peanut butter for ease, affordability, and because it’s easy to find at any grocery store. It gives the same creamy, nutty flavor without hunting for specialty ingredients.
***Adjust the amount of pasta water to get your preferred sauce consistency.
****This dish can be served warm or cold. Serve warm for a comforting meal straight from the skillet, or chill and serve cold for a refreshing noodle salad. Adjust the amount of sauce or pasta water depending on whether you are serving it warm or cold. Cold noodles may absorb more sauce, so toss gently before serving.