2large egg yolks(save the extra whites for another use)
1 ½tspvanilla extract
½tsplemon extract or lemon paste
1 ½tspcorn starch
½tspcoarse Kosher salt(if using table salt, use half the amount)
2cupsall-purpose flour,fluffed, spooned and leveled
¾tspbaking soda
1tbsppoppy seeds
Instructions
Measure the sugar into a mixing bowl, then use a microplane to zest the lemon over the sugar. Use your fingers to rub the lemon zest into the sugar, until moistened.Remove 1/4 cup of the lemon sugar, to use later for rolling the dough balls.
Now cut the lemon in half, and squeeze all the juice out into a liquid measuring cup. You'll need 3 tablespoons lemon juice.
To the remaining 1 cup of lemon sugar, add the softened butter, egg yolks, vanilla extract, lemon extract, corn starch, salt and 3 tbsp lemon juice, and beat on medium speed (with a stand mixer or hand held mixer) for 2-3 minutes, until well combined, and there are no chunks of butter.
Add the flour, baking soda and poppy seeds, and use a spatula to stir everything together into a dough.
Use a small cookie scoop with a release lever to scoop the dough into 28 balls. Roll the balls smooth between your hands, coat in the remaining 1/4 cup lemon sugar, then flatten the balls slightly with your hands.Cover and chill the dough for 1 1/2 hours.
Preheat the oven to 350 F, and position a rack in the center of the oven. Line a baking sheet with parchment paper.
Place the chilled cookies 3 inches apart on the baking sheet (keeping the remaining unbaked cookies refrigerated until ready to bake). Bake for 8 minutes. Take the pan out of the oven, and immediately, use a round cookie cutter or biscuit cutter (with a circumference that's larger than the baked cookies) and "scoot" it around the hot cookies. This pulls in the edges, making the cookies pretty and perfectly round.Cool the cookies on the pan for 2 minutes, then transfer to a cooling rack. Continue to bake the rest of the cookies.
Cool the cookies completely, then store in an airtight container at room temperature for up to 3 days.