In a large pot, boil salted water and cook the spaghetti according to package instructions until al dente. Drain and set aside, reserving about 1/2 cup of pasta water.
In a bowl, mix together the gochujang, sesame oil, soy sauce, and honey (or maple syrup) until well combined. Set aside.
In a large skillet, heat a drizzle of sesame oil over medium heat. Add the minced garlic and grated ginger, sautéing for 1 minute until fragrant.
Stir in the bell pepper and zucchini, cooking for about 3-4 minutes until they start to soften. Then, add the baby spinach and cook until wilted.
Add the cooked pasta to the skillet with the vegetables. Pour the gochujang mixture over the pasta, tossing everything together. If the pasta seems dry, gradually add some reserved pasta water to reach your desired consistency.
Taste your pasta and adjust seasoning as needed; you can add more soy sauce, gochujang, or honey based on your preference for heat and sweetness.
Divide the gochujang pasta into serving bowls. Garnish with chopped green onions and a sprinkle of sesame seeds.
Notes
Adjust the spice level by adding more or less gochujang.