3 cups cake flour
1 1/2 tsp baking powder
1 tsp baking soda
1 tsp ground ginger
 1/2 tsp salt
3/4 c unsalted butter -- softened
 2 c sugar
4 large eggs; allow to come to room temperature then seperate
 2 tbsp lemon juice -- fresh
1 tsp vanilla
 1 1/3 c buttermilk
 1/4 tsp cream of tartar

Preheat oven to 350. Grease and flour 2, 9"x2" round cake pans; flour, tapping out excess. In large bowl, combine flour, baking powder, baking soda, ginger, and salt. Sift into another bowl. In large bowl, beat butter and sugar at medium speed 2 minutes., until fluffy. Beat in egg yolks, one at a time, beating well after each. Beat in lemon juice and vanilla. At low speed, beat in flour mixture (in fourths) alternately with buttermilk (in thirds), beginning and ending with flour mixture; beat just until blended. In small bowl with clean beaters, beat egg whites with cream of tartar until stiff, but not dry, peaks form. With rubber spatula, gently fold egg white mixture, in thirds, into batter. Spread batter in prepared pans. Bake 35 to 40 mins., until cake tester inserted in centers comes out clean. Cool in pans on racks 10 mins. Cool thoroughly before frosting.