Pre-heat oven to 215 degrees
In the bowl of a stand mixer using whisk attachment, beat egg whites on high speed until fluffy, about 2 minutes.
Add in cream of tartar and beat for about 1 more minute.
Add sugar and crushed conversation hearts a spoonful at a time and continue to beat until egg whites are glossy and stiff peaks are formed, about 3-5 more minutes.
Draw heart shapes on a sheet of parchment paper fitted to baking sheet. Turn parchment paper over on pan (so ink from drawings is facing downward).
Put meringue batter in a pastry bag with round tip. Pipe batter tracing heart shapes and completely filling in. Use a toothpick to clean up hearts and get rid of any lumps.
Sprinkle remaining crushed conversation hearts over the top of the hearts.
Bake at 215 degrees for about 40 minutes. Turn oven off and let meringues sit in oven for another hour to completely dry out.