With the appearance, size and color of a rose, the moniker Reef Rose seems to fit. In reality these are the eggs of a large nudibranch, the Spanish dancer. Not at all hard to spot, I had been finding these for years before actually seeing the parent.
I always make a point to check the egg mass closely. There is another nudibranch, a tiny parasitic nudibranch that eats the eggs of the Spanish dancer, a species unsurprisingly called the egg-eating nudibranch.