In a medium saucepan, combine 1 cup water, 0.5 cup apple cider vinegar, and 0.25 cup soy sauce.
Stir in 2 packed tablespoons brown sugar and 1 tablespoon molasses until dissolved.
Add 0.5 teaspoon anchovy paste, 1 teaspoon onion powder, 1 teaspoon garlic powder, 0.5 teaspoon ground ginger, 0.5 teaspoon dry mustard, 0.25 teaspoon black pepper, and 0.125 teaspoon red pepper flakes (plus a pinch of ground cloves, optional).
Place over medium heat and bring to a gentle simmer, stirring occasionally.
Reduce heat to low and simmer gently for 10–15 minutes, until flavors meld and sauce reduces slightly.
Remove from heat and let cool completely.
Optionally strain through a fine-mesh sieve for a smooth texture.
Pour into a clean airtight bottle or jar and refrigerate for up to 2–3 weeks.