Have all ingredients at room temperature, p. 68° to 70°F. Preheat the oven to 325°F. Grease and flour one 9 x 5-inch (8-cup) loaf pan or line the bottom with wax or parchment paper.
Sift the flour twice.
Whisk together in a medium bowl the eggs, vanilla, almond extract, both zests, ssalt and mace.
In a large bowl, beat until creamy the butter and sugar
Gradually add:
Scrape the sides of the bowl and beat on high speed until lightened in color and texture, 3 to 5 minutes. Gradually dribble in the egg mixture, about 1 tbsp at a time, and beat until light and fluffy, 3 to 4 minutes. Add the flour in 3 parts, beating on low speed or stirring with a rubber spatula until smooth and scraping the sides of the bowl as necessary. Scrape the batter into the pan and spread evenly. Bake until a toothpick inserted into the center comes out clean, 1 hour to 1 hour 10 minutes. Let cool in the pan on a rack for 10 minutes. Slide a thin knife around the cake to detach it from the pan. Invert the cake and peel off the paper liner, if using. Let cool right side up on the rack.