Toast the almonds to bring out their flavor and increase their crunchiness: spread nuts onto a baking sheet and bake at 350°F for 7-10 minutes, or until start to turn golden (stirring once while). Set aside to cool completely, then coarsely chop.
Combine flours, starch, gum, baking powder, salt, and zest. Mix well and set aside.
In another bowl, beat eggs until doubled in size, about 4 minutes. Add sugar and combine. Then add butter, oil and extracts, beat well.
Add the dry ingredients in three separate batches, mixing well after each addition. Fold in nuts.
Spoon dough onto a parchment line (and greased) baking sheet. Spread out to the length of the baking sheet, and about 4 inches wide. Flatten gently with hand until smooth.
Bake at 325°F for 35 minutes, until edges start to turn light brown. Remove from oven and let cool for 15 minutes.
Using a sharp knife, slice diagonally into 1/2" thick slices. Turn each onto side, and then return to oven for 10 minutes. Flip to other side, then bake for an additional 10 minutes. Cool completely.
Notes
Other flavorings you can try: dried cranberries, white chocolate chunks, macadamia nuts.