Preheat oven to 350 F. Spray a 9” springform pan with non stick spray.
In a large bowl, combine flour, baking powder, salt and nutmeg. Mix to combine.
In the bowl of an electric mixer, beat butter and sugar until very light and creamy, about 5 minutes.
Add eggs, one at a time, beating well after each addition.
After all the eggs have been added, beat for about 5 minutes.
Add orange zest, vanilla, rum and orange juice. Beat until thoroughly combined.
Add flour in two batches, beating well after each addition.
The batter should have a whipped cream like consistency.
Transfer batter to prepared cake pan.
Bake for 40-45 minutes, until a tester inserted comes our clean.
To make the glaze, melt the jam in the saucepan and add water a little at a time, until you achieve desired consistency. If you prefer a thinner glaze, you can add more water.
Leave the cake to cool in the pan for 15 minutes.
Remove the cake from the pan and brush the glaze on top of the cake.
To prevent the top of the cake crumbling (like mine did), you can just pour the glaze over the cake.