Place the dates in a bowl. Pour over the boiling water. Soak the dates for 4-5 hours or until dates are tender. Drain the dates and set aside.
In a bowl, combine the flour, baking powder, cinnamon, nutmeg and salt. Set the flour mixture aside.
Using an electric mixer, beat the butter and sugar until smooth. Add the eggs and vanilla extract, and mix until smooth. Add the flour mixture and milk. Mix until just combined. Do not overmix.
Fold in dates and walnuts.
Preheat oven to 350 degrees F. Grease a cake pan. Pour the batter into the prepared cake pan.
Bake on the middle rack of the oven until a toothpick inserted in center comes out clean, about 50-60 minutes.
Remove from oven and let cool in the pan for 10 minutes. Run a thin bladed knife around the edges to loosen. Then dust with powdered sugar.