Answer:
0.9975 cup
Step-by-step explanation:
"Unrefined dark crystalline sugar" is what non-chemists call "brown sugar."
200.0 g brown sugar = 1 cup
199.5 g brown sugar = 199.5× 1/200
.0
199.5 g brown sugar = 0.9975 cup
A standard measuring cup is not capable of this precision and, furthermore, the mass of brown sugar you can get into a cup depends on how tightly you pack it.
Your Mole Day cake will be fine if you use 1 cup of brown sugar as usual.
