Oven 350º Grease or line with parchment large baking sheet.
In medium mixing bowl for mixer: Beat butter, sugar, salt, rind, extract, and Baking powder until smooth. Beat in lemon juice and eggs, (batter will look curdled)
On low speed of mixer-add flour, til smooth (dough will be sticky)
Plop dough on baking sheet.Shape into 13" x 3" X 3/4" thick log. Straighten log and smooth the surface.
Bake 25 min. remove from oven all to cool 10-20 min.
Reduce oven 325º
Spray top and sides of log with water bottle. (softening the crust for easier slicing). Wait 5 min
Using serrated knife slice log crosswise into 1/2" slices. Set slice on side on baking sheet. Bake 30-35 min. till very dry and are beginning to turn golden brown on edges. remove fro oven transfer to rack for cooling. Will harden as cools.
Store in air tight container.