Martha's recipe and I have to say it's the very first thing I've made of hers that I am not loving. I had to do some tweaking to the syrup. Actually I followed the directions to the letter and then tried one at the end of the directed cooking time. The syrup was, um, not great and the apple was still hard and the dough wasn't done.
So..... I got rid of the syrup. Made a basic simple syrup with 1 1/2 cups sugar, a teaspoon of vanilla, and a teaspoon of cinnamon in about 2 cups of water. I reduced that at a simmer for about 10 minutes and then poured it over the dumplings.
Then, I put them back in the 350 degree oven for an additional 30 minutes. Much better. Actually quite yummy.