Here's my quick, weekday, not diet friendly lemon poundcake.
1 vanilla gf cake mix (I like Pamela's)
12 T. cold butter, cut into chunks
1/3 c. water
2 t. oil of lemon (or 2 T. lemon juice)
Zest of one lemon
Put your ingredients in a mixing bowl and whir on low for 30 seconds (the butter will still be lumpy, but the cake mix should be all moist). Bake in a loaf pan at 350 for 60-65 minutes.
I like to glaze mine with a mixture of powdered sugar, lemon juice and rum, but that's just me. :D