How to Make It
Preheat the oven to 325°. Butter and flour a 10-inch bundt pan. Sift the flour with the baking powder into a medium bowl. In a large bowl, using an electric mixer, beat the butter with the sugar at high speed until light and fluffy. Beat the egg yolks, honey, pepper, ginger, salt and lemon zest into the butter mixture. Beat in the sifted dry ingredients alternately with the buttermilk.
In a stainless steel bowl, beat the egg whites until they hold firm peaks. Using a spatula, stir one-third of the beaten whites into the cake batter until well mixed. Fold in the remaining whites until just blended. Scrape the batter into the prepared pan and bake for about 1 hour and 10 minutes, or until a cake tester inserted in the center comes out clean. Let the cake cool in the pan for 20 minutes, then unmold it onto a rack and let cool completely before slicing.