3 cups all-purpose flour, divided
1 tablespoon baking powder
3/4 cup half-and-half
2 teaspoons vanilla extract
2 1/4 cups granulated sugar
1 1/2 cups (3 sticks) unsalted butter, at room temperature
6 eggs, at room temperature
1 cup candied ginger, cut into 1/4 inch dice
Heat oven to 350 degrees F. Butter two 9 x 5 1/2 inch loaf pans. Line bottom with wax paper; butter paper. Lightly flour pans and paper.
Sift 2 cups flour with baking powder. Combine half-and-half and vanilla extract.
Beat sugar and butter in large bowl of electric mixer until light and fluffy, scraping sides as necessary. Reduce speed to low and beat in eggs, one at a time. Blend flour mixture and half-and-half alternately into batter, beginning and ending with flour. Increase speed to high and beat just until smooth.
Toss ginger with remaining 1/2 cup flour. Fold into batter. Divide between prepared pans, smoothing tops with spatula. Tap pans lightly on counter top, eliminating air pockets. Bake until cake pulls away from sides of pans and test inserted in centers come out clean about 1 hour.
Cool in pans on racks 30 minutes. Un-mold cakes and cool completely on racks. Wrap tightly in plastic and refrigerate overnight before using. Cakes can be refrigerated up to one week or frozen for 1 month.