Preheat oven to 325. Grease and flour a 10" tube pan or 2 large loaf pans. In a stand mixer (using whisk attachment), cream the butter and cream cheese until smooth and silky.
Slowly add the sugar while the mixer is running, and beat until very fluffy (it will look like whipped cream and may take as long as 5 minutes).
Add the eggs, one at a time, beating well in between each egg. Add the extracts and the lemon zest and mix well.
Replace whisk attachment with paddle attachment. Sift the cake flour into a one cup measure and level off with a knife.
Add flour to butter mixture, one cup at a time, mixing just long enough for the flour to disappear.
Pour batter into prepared tube pan (or two large prepared loaf pans). Hold the filled pan about 6" above your counter and drop it (this will dislodge any big air pockets).
Bake cake for 1 hour 20 minutes. Test for doneness with toothpick test. Let the cake cool about 10 minutes then remove from pan.