Instructions

1. Make the dough: Whisk the flour, baking powder, and salt together in a medium bowl. Set aside.
2. In a large bowl using a hand mixer or a stand mixer fitted with a paddle attachment, beat the butter and granulated sugar together on medium-high speed until creamed, about 2 minutes. Scrape down the sides and up the bottom of the bowl as needed. Add the egg, egg yolk, and vanilla extract and beat on high speed until combined, about 1 minute. Scrape down the sides and up the bottom of the bowl and beat again as needed to combine.
3. Add the flour mixture to the wet ingredients and mix on low speed until combined. Dough will be thick and sticky. Remove from the mixing bowl—no need to rinse out the mixing bowl.
4. Divide the dough in half. It’s ok if the portions aren’t exactly half. If one half is slightly smaller, use that one for the strawberry dough.
5. Make the lemon dough: Place half of the dough back into the mixing bowl, and add in the lemon zest. Mix on low speed until the lemon is combined throughout.
6. Make the strawberry dough: set aside the lemon dough, and add the other half of the dough into the bowl. Add in the freeze dried strawberry powder and milk, and beat on low speed until the dough is combined and a homogenous color.
7. Shape & chill for 60–90 minutes: The doughs are sticky, so just do your best in this step. Place both doughs on a lightly floured work surface. With lightly floured hands, carefully form each dough into a 1-inch-thick rectangle block, about 4×5 inches in size. Wrap both dough blocks up in plastic wrap, parchment paper, or aluminum foil. Refrigerate for 60–90 minutes. This timing is pretty important, since you only want to refrigerate until the dough is less sticky, but still pliable enough to bend and shape. Chilling any longer will make it difficult to roll together. If you need to chill it for longer than 90 minutes, make sure you let it sit at room temperature for 15–30 minutes before continuing with the next step.
8. Roll out the doughs: Remove lemon dough from the refrigerator and unwrap. Keep strawberry dough in the refrigerator. Lightly flour a piece of parchment paper. Note that I like to place the parchment paper on top of a silicone baking mat to prevent it from sliding all over the counter, or you can tape it down. (Do not roll the doughs directly on the counter because you may have a hard time lifting/transferring them.) Using a lightly floured rolling pin, begin rolling out the lemon dough. Flip the dough every now and then between rolls to ensure it’s not sticking to the parchment. Roll out to an 8×14-inch rectangle, and use your hands to ensure the sides are straight and smooth. The thickness will be between 1/8–1/4 inch. Set the dough aside, and it’s most helpful if you refrigerate the lemon dough at this time. Pick up the lemon dough using the parchment paper and place the whole thing in the refrigerator as you roll out the strawberry dough. Lightly dust another piece of parchment paper with flour. Using a lightly floured rolling pin, roll the strawberry dough out to an 8×14-inch rectangle, or very slightly smaller. Remove lemon dough from the refrigerator. Carefully peel the strawberry dough off the parchment and do your best to line it up on top of the lemon dough. Flatten the strawberry dough on top as best you can, gently patting it down to remove any air bubbles between the layers of doughs. Patch any torn strawberry dough pieces back together. And feel free to use a pizza cutter or sharp knife to straighten up any uneven edges.
9. Roll into a log: Starting with a long side, tightly roll the 2 doughs together, making sure there are no gaps between them. You can use the parchment paper under the lemon dough to assist in rolling. Go slowly, and try to roll it as tightly as possible. You can kind of meld the doughs together with your fingers at the beginning to get the roll started. If you notice bare or cracked spots of lemon dough, which usually happens (don’t worry!), just patch it up with your fingers as you go. Doesn’t have to look perfect. Once you have your log of dough, cut it in half, so you have two 7-inch-long dough logs.
10. Chill for 2 more hours: Wrap each dough log in plastic wrap, parchment paper, or aluminum foil and refrigerate for 2 more hours and up to 4 days.
11. Preheat oven to 350°F (177°C). Line 2 baking sheets with parchment paper or silicone baking mats. Set aside.
12. Slice and bake: Slice each log into 14 1/2-inch-thick cookies.
13. Arrange cookies about 2 inches apart on the prepared baking sheets—expect these cookies to expand quite a bit in the oven. If the dough got a little soft from working with it, chill the cookies on the baking sheet in the refrigerator for 10 minutes before baking. Bake for 14–15 minutes or until very lightly browned around the edges.
14. Remove from the oven and allow cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.