01 - Whisk together flour, baking powder, and salt in a medium bowl. Set aside for later use.
02 - Beat butter and sugar in a large bowl until light and fluffy. Add egg and vanilla, mixing until fully combined.
03 - Gradually incorporate the flour mixture into the wet ingredients, mixing just until a cohesive dough forms.
04 - Split dough into three equal portions for flavoring.
05 - Mix one dough portion with cocoa powder until completely incorporated and color is uniform.
06 - Blend second dough portion with freeze-dried strawberry powder. Add pink food coloring if deeper color is desired.
07 - Keep third portion plain for vanilla flavor.
08 - Roll each portion between parchment paper into 10x6 inch rectangles. Refrigerate for 20 to 30 minutes until firm.
09 - Layer chocolate dough on bottom, vanilla in center, and strawberry on top. Press gently to adhere.
10 - Roll stacked dough tightly from the long edge into a log. Wrap in plastic and refrigerate for at least 1 hour until very firm.
11 - Heat oven to 350°F. Line baking sheets with parchment paper.
12 - Cut chilled dough log into 1/4 inch rounds. Arrange 2 inches apart on prepared baking sheets.
13 - Bake for 10 to 12 minutes until edges are lightly golden. Cool on sheet for 5 minutes, then transfer to wire rack.