Preheat oven to 350 F. Spray a 9x13 baking pan with non stick spray.
In a medium bowl, combine flour and dry spices.
In the bowl of an electric mixer, beat butter and sugar until fluffy.
Add eggs, one at a time, until thoroughly combined. Add vanilla extract and beat until combined.
Add half of the dry ingredients and mix to combine. Add the remaining half and mix again until thoroughly combined.
Add sweet potatoes and mix until thoroughly combined. Transfer to prepared pan.
Bake for 1 hour, until knife inserted comes out clean.
To make glaze, combine mango juice and sugar until thoroughly combined. Pour over cake. Leave for 5 minutes.