In a large bowl, cream together the butter and sugar until light and fluffy, about 1 minute. Add the eggs, egg yolks and vanilla extract and beat until well combined.
In a separate bowl, whisk together the flour, baking powder, and salt. Add to the butter mixture and stir until the dough comes together. Divide in half and wrap each half in plastic wrap. Chill for 1 hour, or until firm enough to roll.
Meanwhile, to make the topping, beat the shortening and powdered sugar until creamy. Add the flour, a little at a time, mixing well after each addition. Continue adding until the dough comes together and is smooth. Depending on which topping variations you'll do, you'll want to divide the mixture evenly into desired amount. Then add chocolate to one, cinnamon to one, pink food coloring to another and the orange to the last one. Again, that's only if you're making all four different colors. Knead by hand until evenly colored. Cover with plastic wrap and set aside.
Preheat oven to 375° F. Line two baking sheets with parchment paper and set aside.
Working with one half of dough at a time, roll out onto a lightly floured work surface, to 1/2-inch thick. Use a 2-inch round cookie cutter to cut out the cookies and place on the prepared baking sheets, spacing them out 2-inches apart. Chill until ready to use.
Roll out the topping between two sheets of parchment paper to about 1/4-inch thick. Cut out into 2-inch rounds then score the top with a paring knife or a sharp concha cutter. Place this on top of each cookie. Repeat until all the cookies are covered.
Bake until lightly golden brown around the edges, about 10 to 12 minutes. Cool on baking sheets for 5 minutes before transferring to a wire rack to cool completely. Serve immediately or store in the fridge in an airtight container (with sheets of wax or parchment paper in between) for up to 4 days. Enjoy!