Bring a large pot of salted water to a boil and cook the chickpea spaghetti according to package directions until al dente.
While the pasta cooks, place the diced pancetta in a large skillet over medium heat and cook until crispy and golden brown.
Add the minced garlic to the skillet with the pancetta and sauté for 1 minute until fragrant, then stir in the baby spinach until just wilted.
In a small bowl, whisk together the whole egg, liquid egg whites, grated Pecorino Romano, and freshly cracked black pepper.
Before draining the pasta, reserve about 1/4 cup of the hot pasta cooking water.
Drain the pasta and add it directly to the skillet with the pancetta and spinach, tossing to combine over low heat.
Remove the skillet from the heat entirely to prevent the eggs from scrambling.
Slowly whisk a tablespoon of the reserved pasta water into the egg mixture to temper it, then pour the mixture over the pasta.
Toss vigorously and continuously, adding more pasta water a teaspoon at a time if needed, until a creamy, glossy sauce coats every strand.
Serve immediately with an extra sprinkle of black pepper.