Red food coloring(I use India Tree dyes which are food based, so the red is colored from beets)
Instructions for Rose-Cream filling:
In a mixer using the whisk attachment, combine powdered sugar, milk, salt, vanilla and rose extracts. Beat until smoothly combined.
Slice the butter into half inch thick slices and add separately to the mixture; beating at medium speed to fully combine.
Add shortening and whip on high until the buttercream is fully combined and whipped to double its original volume (approximately 15 minutes). You will see the texture change. Add food coloring drop by drop while mixing to achieve the color you desire.
Filling the cupcakes:
With a sharp knife, cut a finger-width hole in the middle of the cupcake, with a depth of 3/4 of the cupcake's height (e.g. do not cut to the bottom of the cupcake).
Pipe the rose-cream into the hole, filling to be flush with the top of the cupcake.
Frost and decorate as you choose.
When you bite into the cupcake it will look like this!