Having recently knitted with a dk yarn that was more like 4ply, I have just gone to the opposite extreme and knitted with a dk yarn that was more like Aran. This was the Peter Pan Cupcake yarn that was kindly donated to me by Loving Hands.
It is listed on Ravelry as a dk yarn. But, very tellingly, it does not say that on the wrapper. However, it does recommend needle sizes 3.5-4.5mm which would imply that it is a dk yarn. Believe me, it isn't. So, for any project that has to actually fit, a swatch would be essential.
But I had already decided to knit a preemie blanket, so fit wasn't important. I had 100g of white Cupcake which was enough for a 15" square. This will eventually be going off to PreemiesUK. Normally, a yarn this thick would be unsuitable for a newborn baby of any size. But this is so beautifully soft that it will be like wrapping a baby in a cloud.
I still have a lot of the Cupcake in other colours. Ravelry has some pattern suggestions for this yarn. Many people seem to have made blankets and toys with it. A few brave crafters have knitted cardigans and hats. I will probably err on the side of caution/cowardice!