Whip whites until foamy.
Add cream of tartar and whip to soft peaks.
Gradually add sugar and whip to firm peaks.
Draw four 4" hearts on a sheet of parchment paper with a dark pencil.
Place parchment paper on a cookie sheet, drawing side down.
Spoon meringue onto paper the outlined heart shapes.
Build up edges.
Bake at 250° for 1 hour.
Turn oven off and leave meringues in oven for another hour.
Cool completely before filling.
Do not refrigerate, as meringues can absorb moisture and crumble.