Preheat your oven to a warm 350°F (175°C) to get ready for baking.
In your stand mixer, gently cream together the shortening and sugar until the mixture becomes light and fluffy.
Carefully add the eggs, one at a time, mixing on a medium-low speed until they are fully incorporated.
Reduce the mixer speed to low, then pour in the pure vanilla extract, creamy buttermilk, and the vibrant red gel food coloring, mixing until just combined.
In a separate bowl, lightly whisk together the all-purpose flour, rich cocoa powder, and a pinch of salt.
With the mixer still on low speed, gradually add the dry flour mixture to the wet ingredients, blending just until a soft dough forms.
If your dough feels a little dry, you can add a touch more buttermilk, up to an additional ¼ cup, until it reaches a smooth, pipeable consistency.
Spoon small portions of the dough into a piping bag fitted with a 1M or 2D tip, then gently pipe beautiful, individual rosette shapes onto a parchment-lined baking sheet.
Bake for just 6-8 minutes. Don't worry if the centers still look a bit soft—that's how these cookies get their delightful texture! Let them cool completely on the baking sheet to firm up.
Once cool, for a delightful sandwich, spread about 1 tablespoon of your favorite marshmallow buttercream (or a lighter, healthier cream cheese filling for a fresh twist!) onto the flat side of one cookie. Gently top with another cookie and press ever so slightly to create a charming treat. Enjoy these lovely creations in moderation!