Frost your cake with your deep red buttercream
Create your sculpting buttercream by mixing a few tablespoons of buttercream with extra powdered sugar until you get the consistency that you prefer. (This is an optional step.)
Trace an outline of the broken heart onto the front of the cake.
Begin adding the sculpting buttercream inside of the broken heart shape that you traced. You will build this up by periodically chilling the cake in the freezer for 2-5 minutes, then adding more buttercream until you get the desired shape.
Once you have the desired shape, use your clean fingers to smooth out the buttercream and use a toothpick to add details or sharpen edges to acheive the broken heart look that you want.
Break off small pieces of spaghetti noodles and insert them between the two broken heart pieces.
Paint the spaghetti noodle pieces with edible gold dust.