Place the chocolate frosting and the Nutella in the bowl of a large stand mixer fitted with the paddle attachment. Mix on medium-low speed until combined.

Add the powdered sugar and cocoa powder. Mix on low speed until the dry ingredients are completely incorporated, stopping periodically to scrape down the sides and bottom of the bowl as needed.

Candy should be soft enough to shape, but firm enough to hold its body (similar in texture to playdough). If it seems too soft, you can add additional powdered sugar, if it is too stiff, you can knead in an extra spoonful or two of Nutella.

Roll the candy out between two sheets of waxed paper until it is about 1/2-inch thick or a little thicker.

Use a small heart shaped cookie cutter to cut out as many small hearts as you can fit. You can knead the candy scraps back together and roll it out again to cut more hearts. I was able to get 60 hearts using a 1 1/2 inch cutter.

Once you have your hearts cut out, melt the chocolate pieces and shortening on the stovetop, over low heat. Use additional shortening if the chocolate is too thick.

Use a fork to dip a heart into the melted chocolate. Remove it from the coating and scrape the bottom with a spoon or spatula to remove excess chocolate. Place the dipped heart on a foil-covered baking sheet and repeat with remaining hearts and melted chocolate.

If desired, decorate with sprinkles while wet, or drizzle with white, pink, or red candy coating.

Store candy hearts in an airtight container in the refrigerator or at cool room temperature for up to two weeks.