Preheat oven to 350°F. Lightly grease a baking sheet or line with parchment paper.
Beat together butter, sugar, lemon zest, almond extract and baking powder until smooth and creamy.
Beat in the lemon juice and eggs (or egg replacer mixture), the batter may look slightly curdled.
Stir in the flour and mix until just combined.
Scoop the dough onto the baking sheet, and pat into a flattened log about 13″ long x 3″ wide x ¾” thick. Smooth the top using damp fingers or a spatula.
Bake the log for 25 minutes.
Remove from the oven and let cool at least 10 minutes or for up to 25 minutes.
Reduce the oven temperature to 325°F.
Spritz the top of the log with water to soften slightly and wait for 5 minutes, then cut it crosswise into ½” slices.
Set the biscotti, on edge, on the baking sheet and bake for 30~35 minutes or until they feel very dry and are golden around the edges.
Remove from the oven and transfer to a wire rack to cool.