Preheat oven to 375 degrees F. Grease madeleine pan with butter and dust with cocoa powder. Set aside.
Mix flour, cocoa, salt and baking powder in a medium bowl.
Beat sugar and eggs in the bowl of a stand mixer at medium speed for about 5 minutes or until light in color. Beat in flour mixture at low speed until well combined. Beat in melted butter and almond extract until just blended.
Using a tablespoon, measure and level off batter for each madeleine crevice. Push a maraschino cherry into the middle of each madeleine. Bake for 12 minutes or until puffed and golden brown.
Let madeleines cool in pan for 1 minute and then loosen with the point of a small sharp knife. Cool cookies on wire rack.
Melt chocolate with shortening in the microwave in 20-second increments until smooth. Pipe chocolate onto cookies with a piping bag and a #2 round tip. (You can also cut the corner off of a small sandwich bag to pipe the chocolate if you do not have a bag and tip.) Sprinkle sanding sugar or sprinkles over chocolate. Let set in the refrigerator for about 30 minutes or until chocolate is firm.
Madeleines can be stored tightly covered at room temperature up to 24 hours or frozen up to 3 months.
Recipe adapted from How Stuff Works.