Preheat the oven to 350°F (180°C). Line a large cookie sheet with parchment paper. Lightly oil the paper with cooking oil spray. Set aside.

In a mixing bowl, add rolled oats, almond flour, maple syrup, lemon juice, almond extract, and lemon zest if used.

Stir with a rubber spatula at first, then lightly oil your hands and squeeze the dough to bring everything nicely together into a sticky cookie dough.

Scoop out some batter with a cookie dough scoop, press firmly in the scoop to pack the cookie dough, then release it on the baking sheet and flatten the top of the cookies with the palm of your hand. If the sides crack, wet your fingers to pat and reform the cookie.

Repeat until no more cookie dough is left - I made 6 large cookies with the batter.

Bake them for 14-16 minutes at 350°F (180°C) until nicely golden brown.

Let them cool down for 15 minutes at room temperature on the baking sheet. Do not touch them. They firm up as they cool down.

Transfer them to a cooling rack for another 1 hour before serving.

If you like sweet lemon cookies, prepare the lemon glaze by stirring powdered sugar and lemon juice in a small mixing bowl. It should form a thick and creamy paste.

Dip the cooled cookies upside down and twist in the glaze to ice the lemon cookies, then flip and place on a rack to let the excess glaze run down.

Sprinkle extra lemon zest on top if you like its tangy flavor and cool the cookies in the fridge an hour to set the icing.