Once your sweet potato is all smooth, set it aside for later. This will allow it to cool off a little.
Preheat the oven to 375 degrees. I like to place my pans on top of the stove above the oven while they are rising, because it is a little warmer there.
Mix together sweet potato puree, brown sugar, cinnamon and pear ginger syrup. Spread 1/2 of the filling over top of the butter.