Sift together the flour, baking powder & salt. Set aside.
Remove from heat and stir in the brown sugar and vanilla. You can transfer this to the bowl of an electric mixer on low speed.
Stir/mix for several minutes to start to dissolve as much of the sugar as possible. It will still be a little grainy at this point.
Bake for about 40 -50 minutes at 325 degrees F (300 F for glass bakeware) or until a wooden toothpick inserted into the center comes out clean.