In a small saucepan, melt the chocolate, shortening, and butter over low heat.

Allow it to cool for at least 15 minutes.

Preheat your oven to 350°F.

Lightly grease a cookie sheet or line it with parchment paper.

In a large bowl, combine the next five ingredients (sugar, eggs, baking powder, baking soda, and salt).

Stir in the melted chocolate mixture and vanilla.

Add the flour and cocoa powder.

If necessary, cover and chill the dough for 30 to 60 minutes, or until it's easy to handle.

Shape the dough into 1¹⁄₂-inch balls.

Roll each ball in sanding or coarse sugar, then place them 2 inches apart on the prepared cookie sheet.

Bake for 8 to 10 minutes or until the edges are firm, and cracks appear slightly moist.

Allow the cookies to cool on the cookie sheet for 2 minutes, then transfer them to a wire rack to cool completely.