Add flour, that has been sifted with baking powder, alternately with the milk.
Add lemon rind.
Turn into deep cupcake pans that have been well greased.
Bake in a quick oven (that's code for 425 degrees Fahrenheit) until done, 15 minutes should do.
Meanwhile, while baking, get double boiler out and combine lemon butter cream ingredients; sugar, dash salt, juice and rind of 1 lemon, 3 egg yolks and 2 tablespoons butter over hot water, until sugar is dissolved and mixture is slightly thickened; cool. This mixture can be spread between layers of cakes and is especially good on cupcakes on previous page when mixed with whipped cream which is the 1 cup whipping cream beaten, I think you could use Cool Whip here.