I was 9 when Szechuan sauce graced sauce pumps across the nation, so naturally, I can't remember at all what it tastes like. But with the help of some actual Szechuan sauce (like, the stuff from Sichuan), a Redditor's diligent recreation, a fast-food-secret: mixing things together in different ways and repackaging it, we might just come close!

Method: Standard Szechuan Sauce

Dry roast 1 ounce of red dried Chinese chilis: Sauté them in an un-oiled pan until fragrant. Add boiling water to the pan and let the peppers steep for 30 minutes.
Toast Szechuan peppercorns. Once toasted, place in grinder and grind until finely ground. Set aside.
Add peppers to food processor along with fresh ginger and blend until paste-like.
Sweat some garlic in oil in a pan and add blended peppers. Sauté for about 2 minutes and then add 1 Tbsp sesame seed oil, some rice wine vinegar, a few Tbsp of soy sauce, some of our freshly ground Szechuan peppercorns, and about 1 Tbsp of brown sugar. Mix until combined.

Sweat some garlic and oil in a pan until fragrant.
Add balsamic vinegar, soy sauce, a few Tbsp of plum sake, a good helping of sriracha sauce, 4 Tbsp of brown sugar, and if you want some heat, add chili paste from previous episode. Also we are going to crush a knob of fresh ginger in there.
Sauté for about 5 minutes until everything is soft and syrupy.