01 - Whisk together flour, baking powder, and salt in a medium bowl until well combined. Set aside for later use.
02 - Beat softened butter and granulated sugar in a large bowl until mixture appears light and fluffy. Add egg and vanilla extract, mixing until fully incorporated.
03 - Gradually add flour mixture to wet ingredients, mixing just until dough comes together. Avoid overmixing to maintain tender texture.
04 - Split dough into three equal portions. Set aside one portion for vanilla layer.
05 - Mix one dough portion with cocoa powder until color is uniform and completely incorporated.
06 - Mix remaining dough portion with freeze-dried strawberry powder until even color is achieved. Add pink food coloring drop by drop if deeper color is desired.
07 - Roll each dough portion between parchment sheets into 10x6 inch rectangles. Refrigerate all layers for 20 to 30 minutes until firm to the touch.
08 - Layer chocolate dough on bottom, vanilla in center, and strawberry on top. Press layers gently to adhere without compressing.
09 - Tightly roll stacked dough starting from long edge into a uniform log. Wrap in plastic wrap and refrigerate for minimum 1 hour until very firm.
10 - Preheat oven to 350°F. Line baking sheets with parchment paper.
11 - Cut chilled log into 1/4-inch thick rounds. Arrange cookies 2 inches apart on prepared baking sheets.
12 - Bake for 10 to 12 minutes until edges turn lightly golden. Allow cookies to rest on baking sheet for 5 minutes, then transfer to wire rack to cool completely.