Preheat oven to 325°F
Cream together butter and granulated sugar until light and fluffy
Add room temperature eggs one at a time, beating well after each addition
In a separate bowl, whisk together flour, baking powder, salt, cinnamon, nutmeg, and ginger
Alternate adding dry ingredients and evaporated milk to the butter mixture, beginning and ending with dry ingredients
Fold in mashed sweet potato and vanilla extract
Pour batter into a greased pound cake pan
Bake at 325°F for about 1.5 hours until a toothpick inserted in the center comes out clean
Cool cake completely
For glaze: Melt butter and mix with sifted powdered sugar, heavy cream, vanilla extract, and salt until smooth
Drizzle glaze over cooled cake
