Preheat oven to 325 degrees. Generously grease and flour a 10 cup bundt pan.

In a large bowl, sift together the flour, baking powder and salt. In another large bowl, beat the butter and sugar with an electric mixer until light and fluffy. Add the eggs one at a time, beating well after each addition.

Mix the sour cream, lemon juice, ginger, lemon zest and vanilla into the butter mixture until smooth. Mix half of the flour mixture into the wet ingredients, followed by all of the buttermilk. Mix in the remaining flour and stir until just combined.

Transfer the batter to the prepared pan. Bake for 70-80 minutes, or until a toothpick inserted in the center comes out clean. Cool cake in pan for 10 minutes before turning onto a wire rack to cool completely.

Meanwhile, make the lemon frosting by beating the cream cheese, butter, lemon juice and zest, vanilla and salt until smooth. Mix in the powdered sugar, one cup at a time, until frosting reaches desired consistency. Spread or pipe frosting over cooled cake.