Preheat oven to 350ºF.
Cream butter and sugar together.
Add eggs one at a time mixing after each egg.
If you are adding anise, fennel seed, lemon zest, or orange zest, add it here.
Add water, almonds, lemon zest, and baking powder to the mixture. Mix until incorporated.
Add flour and stir in by hand. Do not over mix.
Sprinkle a cutting board or counter with flour. Lay the dough on the flour and sprinkle it with more flour. Do not knead.
Shape the dough into the shape of a log approximately 14 inches long. Divide into 4 equal parts and shape into a thin log just shorter than the length of the cookie sheet you will be using.
Line two cookie sheets with aluminum foil and two of the dough logs on each one. Flatten the edges so that they are approximately 2 inches wide.
Bake for 30 minutes.
Remove from the oven and cool completely.
Cut into slices approximately ¾ inch wide.
Bake again for 25 minutes.
Cool and serve.