Cream together unsalted butter and powdered sugar until light and fluffy, about 2-3 minutes. Add eggs and milk, blending until combined. Gradually incorporate flour, salt, vanilla, and almond extract until a soft dough forms.

Divide the dough into three equal parts. Leave one part plain, color the second with purple gel and the third with black gel. Mix until colors are vibrant.

Roll each colored dough between parchment paper into rectangles about ¼ inch thick. Place the black dough first, then the plain white dough on top. Roll them together gently.

Roll the purple dough into another rectangle. Sprinkle purple sprinkles over it, leaving a border. Roll it up tightly to create the colorful center.

Position the purple log at one end of the stacked black and white dough. Roll the black and white dough over the purple log, forming a spiral shape.

Coat the log's outer layer with black sprinkles. Wrap tightly in plastic wrap and refrigerate for at least 1 hour.

Preheat your oven to 375°F (190°C). Slice the chilled log into ¼-inch thick rounds. Place on a parchment-lined baking sheet, adding extra colored sprinkles before baking for 10 minutes.

Let cookies cool on the pan for 10 minutes, then transfer to a wire rack to cool completely before serving.