Heat the oven to 375°F, and prepare two cookie sheets with parchment paper or a Silpat
In a large mixing bowl beat the butter and shortening until fluffy on medium speed. You can also use your stand mixer with the paddle attachment.
Add the sugar, the egg and egg yolks and vanilla then mix on medium speed until combined, scraping the sides of the bowl with a rubber spatula
Mix in the flour, baking powder, and salt on medium speed until combined, forming a soft dough.
Remove ¾ cup of the dough to a small bowl and add the sifted powdered sugar, cocoa powder, red food coloring, and melted butter. Mix well with a spoon to combine.
Pour the sprinkles into a large bowl, that is big enough to roll the cookie dough balls around.
Measure out 1 tablespoon of vanilla dough and make 25 balls with the dough
Measure out 1 teaspoon of the red velvet dough and shape it into 25 1" balls.
Flatten the vanilla-flavored dough balls into a disk and place a red velvet dough ball in the center and mold the dough around it to make a round ball.
Roll the dough ball several times in your hands to warm the dough up. The dough ball needs to be warm for the nonpareils to stick to the dough.
Roll the ball in the nonpareil sprinkles and place on a parchment-lined baking sheet.
Bake for 12 minutes at 375 degrees. Remove and let cool for 5 minutes then move to a cooling rack.
Store the cookies in an airtight container for several days.