Place an oven rack in the center of the oven, and preheat the oven to 325°F. Lightly grease and flour a 10" tube pan and set aside.
Place the butter in a large mixing bowl, and beat with an electric mixer on low speed until the butter is lightly creamed, 30 seconds. With the mixer running on low, gradually add the sugar, beating until the mixture is well creamed and fluffy, 2 minutes. Turn off the mixer and scrape down the sides of the bowl with a rubber spatula.
Add the eggs to the sugar and butter mixture, one at a time, beating well after each addition. In a separate bowl, combine the flour and the salt, then add to the creamed mixture in thirds, beating on low during each addition. Fold in the lemon zest, almond extract, or vanilla, if desired.
Pour the batter into the prepared pan, smooth the top, and place the pan in the oven. Bake until the top of the cake is golden brown and firm to the touch, 1 hour 20 to 25 minutes.
Remove the pan from the oven, and place on a wire rack to cool for 20 minutes. Run a knife around the edges of the pan, and invert the cake once and then again so it rests right side up. Let cool on the rack completely, 1 hour, before slicing.