6 tablespoons (84 g) unsalted butter, at room temperature
3/4 cups (150 g) sugar
1 tablespoon (21 g) light corn syrup (this is NOT high fructose corn syrup!)
2 egg whites (60 g) at room temperature
2 teaspoons pure vanilla extract
1/4 cup freshly squeezed lemon juice (from about 1 lemon), reduced by half
1 3/4 cups (245 g) all-purpose gluten free flour (I used Better Batter)
1 teaspoon xanthan gum (omit if your blend already contains it)
4 tablespoons (36 g) cornstarch
1/2 teaspoon kosher salt
1 teaspoon baking powder
1/2 teaspoon baking soda
3 teaspoons lemon zest (again, from 1 lemon)
1 tablespoon poppy seeds
Coarse sugar, for rolling (I used Sugar in the Raw) (optional)
Preheat your oven to 350°F. Line rimmed baking sheets with unbleached parchment paper and set aside.
In the bowl of a stand mixer fitted with the paddle attachment (or a large bowl with a hand mixer), cream the butter on medium-high speed until light and fluffy. Add the sugar, corn syrup, egg whites, vanilla and reduced lemon juice, beating well after each addition. In a separate medium-size bowl, place the flour blend, xanthan gum, cornstarch, salt, baking powder, baking soda, lemon zest and poppy seeds, and whisk to combine well, working out any clumps in the lemon zest. Add the dry ingredients to the wet ingredients in the mixer bowl in 3 batches, beating until just combined after each addition. The dough should be fluffy and light. Transfer the dough to a large piece of plastic wrap, wrap tightly and refrigerate for about 15 minutes or until chilled.
Once the dough has chilled, scoop it by the scant tablespoonful onto the rimmed baking sheets, placing them about 2 inches apart. Roll tightly into balls, roll in the coarse sugar to coat completely, and then press down into a disk a bit thicker than 1/8-inch thick. (The original recipe is pressed into a disk that is 1/4-inch thick, but with so much less butter, these cookies don’t spread much in the oven.) Place in the center of the preheated oven and bake until the edges of the cookies are lightly golden brown (about 10 minutes). Allow to cool on the baking sheet for 10 minutes before transferring to a wire rack to cool completely.
P.S. Did you remember your copy of Gluten Free on a Shoestring Bakes Bread? Thank you thank you thank you!