Preheat your oven to 350°F (175°C). Line your baking sheets with parchment paper.
In a large mixing bowl, whisk together the bleached cake flour and baking powder. Set aside.
In another bowl, combine the granulated sugar and almond paste, mixing until the almond paste is finely crumbled.
Add the eggs, vanilla extract, and salt to the almond paste mixture. Beat with a whisk until well combined. Gradually add the melted butter, mixing until smooth.
Slowly add the flour mixture to the wet ingredients, stirring gently with a spatula until just combined. Be careful not to overmix.
Divide the batter into three equal portions. Use food coloring to dye each portion a different shade, creating an ombre effect.
Spread the lightest batter evenly onto the prepared baking sheet. Bake for about 10-12 minutes, or until lightly golden. Remove from the oven and let cool slightly before transferring to a cooling rack.
Repeat the baking process with the medium and dark batter layers, ensuring they cool completely before assembling.
Once all layers are cool, spread a thin layer of apricot jam on the lightest layer, then stack the medium layer on top, repeating the process with the dark layer.
In a small saucepan, melt the bittersweet chocolate with the tablespoon of unsalted butter over low heat, stirring until smooth.
Pour the melted chocolate over the stacked layers, allowing it to drip down the sides. Let the chocolate set before slicing the cookies into squares or rectangles.