While the cake cools, make the glaze by bringing the sugar, butter, water, and nutmeg to a boil in a small saucepan. Boil 5 minutes stirring constantly. Remove the glaze from the heat and stir in the rum and brandy. The glaze will be very thin. After the cake has cooled for 10 minutes, invert it onto a large platter or cutting board, or sheet of heavy foil. Brush hot glaze over the entire top of warm cake until all of it is used. Let the cake sit at room temperature uncovered for several hours or overnight.