Preheat oven to 350ºF / 175ºC. Line two baking sheets with parchment paper.
In the bowl of a stand mixer with the paddle attachment, add your cream cheese and unsalted butter.
Add sugar, salt, vanilla extract, and egg. Turn your mixer on the lowest speed available. We don't want to incorporate any air into the dough. Air will cause spreading! Scrape down the bottom and sides of the bowl.
Add the flour. Mix until it all comes together. It will to gather onto the paddle. It doesn't take long, so don't walk away from it. Turn the mixer off and touch the dough. If you can leave an imprint with your finger without the dough sticking to it, its ready.
On a lightly floured surface roll out the dough. Cut into heart shapes using a floured cookie cutter.
Place on the baking sheets and bake them for 12-14 minutes. Cool on rack.
Melt Chocolate and dip half of the cookie. Place on a parchment lined cookie sheet and refrigerate for 15 minutes to harden chocolate. Dust with sprinkles if desired.