In a medium bowl, whisk together the flour, baking powder, and salt.
In a large bowl, beat the softened butter and granulated sugar until light and fluffy.
Mix in the egg, vanilla extract, and almond extract until well combined.
Gradually add the dry ingredients to the wet mixture, mixing until a soft dough forms.
Evenly divide the dough into three portions.
Leave one portion plain for the vanilla layer.
To the second portion, add strawberry jam and a few drops of red or pink food coloring. Mix until well combined.
To the third portion, stir in the unsweetened cocoa powder until fully incorporated.
Line a 9x5-inch loaf pan with parchment paper, leaving overhang on the sides. Press the strawberry dough evenly into the bottom. Add the vanilla dough on top, pressing evenly. Finish with the chocolate dough, pressing evenly.
Cover the pan and refrigerate for at least 1 hour until firm.
Preheat the oven to 350°F. Line baking sheets with parchment paper.
Lift the chilled dough from the pan using the parchment overhang. Slice lengthwise into 3 pieces. Cut each piece into ¼-inch thick slices.
Place slices 2 inches apart on prepared baking sheets. Bake for 10-12 minutes or until edges are set.
Allow cookies to cool on the baking sheet for 5 minutes, then transfer to wire racks to cool completely.