Preheat the oven to 180℃/350℉. Line a cookie sheet with parchment/butter paper.

Whisk together sugar and butter until well-blended (no need to cream).

Add vanilla extract, orange essence, and lemon zest. Also, add eggs (one at a time) and mix till well combined.

Sift in flour and baking powder. Add almonds and mix to form a heavy dough.

Sprinkle some flour on a flat/rolling surface. Place the dough on the surface and divide into two equal pieces. Form each piece into a rectangle with ½ to 1-inch thickness.

Place these rectangles on the prepared sheets. Sprinkle some sugar on top(optional).

Bake in the preheated oven until golden brown, 25 to 30 minutes. Let them sit until cool enough to handle, about 15 minutes.

Slice each rectangle crosswise into about 1/2-inch-thick slices. Place slices cut-sides up back on the cookie sheets.