Beat butter and sugar in a bowl. Next, beat in vanilla and eggs, and then add lemon juice and mix. Whisk flour, salt, baking powder, and zest in a separate bowl then add dry ingredients. Mix in nuts and chill.
Transfer chilled dough to a lightly floured work surface. Divide in half and form each half into two logs Place logs on the prepared baking sheet and bake. Cool, slice, and bake again.